Release 4.7 block/cfq-iosched.c

/*
 *  CFQ, or complete fairness queueing, disk scheduler.
 *
 *  Based on ideas from a previously unfinished io
 *  scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
 *
 *  Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
 */
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
#include <linux/jiffies.h>
#include <linux/rbtree.h>
#include <linux/ioprio.h>
#include <linux/blktrace_api.h>
#include <linux/blk-cgroup.h>
#include "blk.h"

/*
 * tunables
 */
/* max queue in one round of service */

static const int cfq_quantum = 8;

static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
/* maximum backwards seek, in KiB */

static const int cfq_back_max = 16 * 1024;
/* penalty of a backwards seek */

static const int cfq_back_penalty = 2;

static const int cfq_slice_sync = HZ / 10;

static int cfq_slice_async = HZ / 25;

static const int cfq_slice_async_rq = 2;

static int cfq_slice_idle = HZ / 125;

static int cfq_group_idle = HZ / 125;

static const int cfq_target_latency = HZ * 3/10; 
/* 300 ms */

static const int cfq_hist_divisor = 4;

/*
 * offset from end of service tree
 */

#define CFQ_IDLE_DELAY		(HZ / 5)

/*
 * below this threshold, we consider thinktime immediate
 */

#define CFQ_MIN_TT		(2)


#define CFQ_SLICE_SCALE		(5)

#define CFQ_HW_QUEUE_MIN	(5)

#define CFQ_SERVICE_SHIFT       12


#define CFQQ_SEEK_THR		(sector_t)(8 * 100)

#define CFQQ_CLOSE_THR		(sector_t)(8 * 1024)

#define CFQQ_SECT_THR_NONROT	(sector_t)(2 * 32)

#define CFQQ_SEEKY(cfqq)	(hweight32(cfqq->seek_history) > 32/8)


#define RQ_CIC(rq)		icq_to_cic((rq)->elv.icq)

#define RQ_CFQQ(rq)		(struct cfq_queue *) ((rq)->elv.priv[0])

#define RQ_CFQG(rq)		(struct cfq_group *) ((rq)->elv.priv[1])


static struct kmem_cache *cfq_pool;


#define CFQ_PRIO_LISTS		IOPRIO_BE_NR

#define cfq_class_idle(cfqq)	((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)

#define cfq_class_rt(cfqq)	((cfqq)->ioprio_class == IOPRIO_CLASS_RT)


#define sample_valid(samples)	((samples) > 80)

#define rb_entry_cfqg(node)	rb_entry((node), struct cfq_group, rb_node)

/* blkio-related constants */

#define CFQ_WEIGHT_LEGACY_MIN	10

#define CFQ_WEIGHT_LEGACY_DFL	500

#define CFQ_WEIGHT_LEGACY_MAX	1000


struct cfq_ttime {
	
unsigned long last_end_request;

	
unsigned long ttime_total;
	
unsigned long ttime_samples;
	
unsigned long ttime_mean;
};

/*
 * Most of our rbtree usage is for sorting with min extraction, so
 * if we cache the leftmost node we don't have to walk down the tree
 * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should
 * move this into the elevator for the rq sorting as well.
 */

struct cfq_rb_root {
	
struct rb_root rb;
	
struct rb_node *left;
	
unsigned count;
	
u64 min_vdisktime;
	
struct cfq_ttime ttime;
};

#define CFQ_RB_ROOT	(struct cfq_rb_root) { .rb = RB_ROOT, \
                        .ttime = {.last_end_request = jiffies,},}

/*
 * Per process-grouping structure
 */

struct cfq_queue {
	/* reference count */
	
int ref;
	/* various state flags, see below */
	
unsigned int flags;
	/* parent cfq_data */
	
struct cfq_data *cfqd;
	/* service_tree member */
	
struct rb_node rb_node;
	/* service_tree key */
	
unsigned long rb_key;
	/* prio tree member */
	
struct rb_node p_node;
	/* prio tree root we belong to, if any */
	
struct rb_root *p_root;
	/* sorted list of pending requests */
	
struct rb_root sort_list;
	/* if fifo isn't expired, next request to serve */
	
struct request *next_rq;
	/* requests queued in sort_list */
	
int queued[2];
	/* currently allocated requests */
	
int allocated[2];
	/* fifo list of requests in sort_list */
	
struct list_head fifo;

	/* time when queue got scheduled in to dispatch first request. */
	
unsigned long dispatch_start;
	
unsigned int allocated_slice;
	
unsigned int slice_dispatch;
	/* time when first request from queue completed and slice started. */
	
unsigned long slice_start;
	
unsigned long slice_end;
	
long slice_resid;

	/* pending priority requests */
	
int prio_pending;
	/* number of requests that are on the dispatch list or inside driver */
	
int dispatched;

	/* io prio of this group */
	

unsigned short ioprio, org_ioprio;
	
unsigned short ioprio_class;

	
pid_t pid;

	
u32 seek_history;
	
sector_t last_request_pos;

	
struct cfq_rb_root *service_tree;
	
struct cfq_queue *new_cfqq;
	
struct cfq_group *cfqg;
	/* Number of sectors dispatched from queue in single dispatch round */
	
unsigned long nr_sectors;
};

/*
 * First index in the service_trees.
 * IDLE is handled separately, so it has negative index
 */

enum wl_class_t {
	
BE_WORKLOAD = 0,
	
RT_WORKLOAD = 1,
	
IDLE_WORKLOAD = 2,
	
CFQ_PRIO_NR,
};

/*
 * Second index in the service_trees.
 */

enum wl_type_t {
	
ASYNC_WORKLOAD = 0,
	
SYNC_NOIDLE_WORKLOAD = 1,
	
SYNC_WORKLOAD = 2
};


struct cfqg_stats {
#ifdef CONFIG_CFQ_GROUP_IOSCHED
	/* number of ios merged */
	
struct blkg_rwstat		merged;
	/* total time spent on device in ns, may not be accurate w/ queueing */
	
struct blkg_rwstat		service_time;
	/* total time spent waiting in scheduler queue in ns */
	
struct blkg_rwstat		wait_time;
	/* number of IOs queued up */
	
struct blkg_rwstat		queued;
	/* total disk time and nr sectors dispatched by this group */
	
struct blkg_stat		time;
#ifdef CONFIG_DEBUG_BLK_CGROUP
	/* time not charged to this cgroup */
	
struct blkg_stat		unaccounted_time;
	/* sum of number of ios queued across all samples */
	
struct blkg_stat		avg_queue_size_sum;
	/* count of samples taken for average */
	
struct blkg_stat		avg_queue_size_samples;
	/* how many times this group has been removed from service tree */
	
struct blkg_stat		dequeue;
	/* total time spent waiting for it to be assigned a timeslice. */
	
struct blkg_stat		group_wait_time;
	/* time spent idling for this blkcg_gq */
	
struct blkg_stat		idle_time;
	/* total time with empty current active q with other requests queued */
	
struct blkg_stat		empty_time;
	/* fields after this shouldn't be cleared on stat reset */
	
uint64_t			start_group_wait_time;
	
uint64_t			start_idle_time;
	
uint64_t			start_empty_time;
	
uint16_t			flags;
#endif	/* CONFIG_DEBUG_BLK_CGROUP */
#endif	/* CONFIG_CFQ_GROUP_IOSCHED */
};

/* Per-cgroup data */

struct cfq_group_data {
	/* must be the first member */
	
struct blkcg_policy_data cpd;

	
unsigned int weight;
	
unsigned int leaf_weight;
};

/* This is per cgroup per device grouping structure */

struct cfq_group {
	/* must be the first member */
	
struct blkg_policy_data pd;

	/* group service_tree member */
	
struct rb_node rb_node;

	/* group service_tree key */
	
u64 vdisktime;

	/*
         * The number of active cfqgs and sum of their weights under this
         * cfqg.  This covers this cfqg's leaf_weight and all children's
         * weights, but does not cover weights of further descendants.
         *
         * If a cfqg is on the service tree, it's active.  An active cfqg
         * also activates its parent and contributes to the children_weight
         * of the parent.
         */
	
int nr_active;
	
unsigned int children_weight;

	/*
         * vfraction is the fraction of vdisktime that the tasks in this
         * cfqg are entitled to.  This is determined by compounding the
         * ratios walking up from this cfqg to the root.
         *
         * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all
         * vfractions on a service tree is approximately 1.  The sum may
         * deviate a bit due to rounding errors and fluctuations caused by
         * cfqgs entering and leaving the service tree.
         */
	
unsigned int vfraction;

	/*
         * There are two weights - (internal) weight is the weight of this
         * cfqg against the sibling cfqgs.  leaf_weight is the wight of
         * this cfqg against the child cfqgs.  For the root cfqg, both
         * weights are kept in sync for backward compatibility.
         */
	
unsigned int weight;
	
unsigned int new_weight;
	
unsigned int dev_weight;

	
unsigned int leaf_weight;
	
unsigned int new_leaf_weight;
	
unsigned int dev_leaf_weight;

	/* number of cfqq currently on this group */
	
int nr_cfqq;

	/*
         * Per group busy queues average. Useful for workload slice calc. We
         * create the array for each prio class but at run time it is used
         * only for RT and BE class and slot for IDLE class remains unused.
         * This is primarily done to avoid confusion and a gcc warning.
         */
	
unsigned int busy_queues_avg[CFQ_PRIO_NR];
	/*
         * rr lists of queues with requests. We maintain service trees for
         * RT and BE classes. These trees are subdivided in subclasses
         * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE
         * class there is no subclassification and all the cfq queues go on
         * a single tree service_tree_idle.
         * Counts are embedded in the cfq_rb_root
         */
	
struct cfq_rb_root service_trees[2][3];
	
struct cfq_rb_root service_tree_idle;

	
unsigned long saved_wl_slice;
	
enum wl_type_t saved_wl_type;
	
enum wl_class_t saved_wl_class;

	/* number of requests that are on the dispatch list or inside driver */
	
int dispatched;
	
struct cfq_ttime ttime;
	
struct cfqg_stats stats;	/* stats for this cfqg */

	/* async queue for each priority case */
	
struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
	
struct cfq_queue *async_idle_cfqq;

};


struct cfq_io_cq {
	
struct io_cq		icq;		/* must be the first member */
	
struct cfq_queue	*cfqq[2];
	
struct cfq_ttime	ttime;
	
int			ioprio;		/* the current ioprio */
#ifdef CONFIG_CFQ_GROUP_IOSCHED
	
uint64_t		blkcg_serial_nr; /* the current blkcg serial */
#endif
};

/*
 * Per block device queue structure
 */

struct cfq_data {
	
struct request_queue *queue;
	/* Root service tree for cfq_groups */
	
struct cfq_rb_root grp_service_tree;
	
struct cfq_group *root_group;

	/*
         * The priority currently being served
         */
	
enum wl_class_t serving_wl_class;
	
enum wl_type_t serving_wl_type;
	
unsigned long workload_expires;
	
struct cfq_group *serving_group;

	/*
         * Each priority tree is sorted by next_request position.  These
         * trees are used when determining if two or more queues are
         * interleaving requests (see cfq_close_cooperator).
         */
	
struct rb_root prio_trees[CFQ_PRIO_LISTS];

	
unsigned int busy_queues;
	
unsigned int busy_sync_queues;

	
int rq_in_driver;
	
int rq_in_flight[2];

	/*
         * queue-depth detection
         */
	
int rq_queued;
	
int hw_tag;
	/*
         * hw_tag can be
         * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection)
         *  1 => NCQ is present (hw_tag_est_depth is the estimated max depth)
         *  0 => no NCQ
         */
	
int hw_tag_est_depth;
	
unsigned int hw_tag_samples;

	/*
         * idle window management
         */
	
struct timer_list idle_slice_timer;
	
struct work_struct unplug_work;

	
struct cfq_queue *active_queue;
	
struct cfq_io_cq *active_cic;

	
sector_t last_position;

	/*
         * tunables, see top of file
         */
	
unsigned int cfq_quantum;
	
unsigned int cfq_fifo_expire[2];
	
unsigned int cfq_back_penalty;
	
unsigned int cfq_back_max;
	
unsigned int cfq_slice[2];
	
unsigned int cfq_slice_async_rq;
	
unsigned int cfq_slice_idle;
	
unsigned int cfq_group_idle;
	
unsigned int cfq_latency;
	
unsigned int cfq_target_latency;

	/*
         * Fallback dummy cfqq for extreme OOM conditions
         */
	
struct cfq_queue oom_cfqq;

	
unsigned long last_delayed_sync;
};

static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
static void cfq_put_queue(struct cfq_queue *cfqq);



static struct cfq_rb_root *st_for(struct cfq_group *cfqg,
					    enum wl_class_t class,
					    enum wl_type_t type)
{
	if (!cfqg)
		return NULL;

	if (class == IDLE_WORKLOAD)
		return &cfqg->service_tree_idle;

	return &cfqg->service_trees[class][type];
}

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enum cfqq_state_flags {
	
CFQ_CFQQ_FLAG_on_rr = 0,	/* on round-robin busy list */
	
CFQ_CFQQ_FLAG_wait_request,	/* waiting for a request */
	
CFQ_CFQQ_FLAG_must_dispatch,	/* must be allowed a dispatch */
	
CFQ_CFQQ_FLAG_must_alloc_slice,	/* per-slice must_alloc flag */
	
CFQ_CFQQ_FLAG_fifo_expire,	/* FIFO checked in this slice */
	
CFQ_CFQQ_FLAG_idle_window,	/* slice idling enabled */
	
CFQ_CFQQ_FLAG_prio_changed,	/* task priority has changed */
	
CFQ_CFQQ_FLAG_slice_new,	/* no requests dispatched in slice */
	
CFQ_CFQQ_FLAG_sync,		/* synchronous queue */
	
CFQ_CFQQ_FLAG_coop,		/* cfqq is shared */
	
CFQ_CFQQ_FLAG_split_coop,	/* shared cfqq will be splitted */
	
CFQ_CFQQ_FLAG_deep,		/* sync cfqq experienced large depth */
	
CFQ_CFQQ_FLAG_wait_busy,	/* Waiting for next request */
};


#define CFQ_CFQQ_FNS(name)						\
static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq)         \
{                                                                       \
        (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name);                   \
}                                                                       \
static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq)        \
{                                                                       \
        (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name);                  \
}                                                                       \
static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq)         \
{                                                                       \
        return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0;      \
}


CFQ_CFQQ_FNS(on_rr);

CFQ_CFQQ_FNS(wait_request);

CFQ_CFQQ_FNS(must_dispatch);

CFQ_CFQQ_FNS(must_alloc_slice);

CFQ_CFQQ_FNS(fifo_expire);

CFQ_CFQQ_FNS(idle_window);

CFQ_CFQQ_FNS(prio_changed);

CFQ_CFQQ_FNS(slice_new);

CFQ_CFQQ_FNS(sync);

CFQ_CFQQ_FNS(coop);

CFQ_CFQQ_FNS(split_coop);

CFQ_CFQQ_FNS(deep);

CFQ_CFQQ_FNS(wait_busy);

#undef CFQ_CFQQ_FNS

#if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)

/* cfqg stats flags */

enum cfqg_stats_flags {
	
CFQG_stats_waiting = 0,
	
CFQG_stats_idling,
	
CFQG_stats_empty,
};


#define CFQG_FLAG_FNS(name)						\
static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats)     \
{                                                                       \
        stats->flags |= (1 << CFQG_stats_##name);                       \
}                                                                       \
static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats)    \
{                                                                       \
        stats->flags &= ~(1 << CFQG_stats_##name);                      \
}                                                                       \
static inline int cfqg_stats_##name(struct cfqg_stats *stats)           \
{                                                                       \
        return (stats->flags & (1 << CFQG_stats_##name)) != 0;          \
}                                                                       \

CFQG_FLAG_FNS(waiting)
CFQG_FLAG_FNS(idling)
CFQG_FLAG_FNS(empty)

#undef CFQG_FLAG_FNS

/* This should be called with the queue_lock held. */


static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats)
{
	unsigned long long now;

	if (!cfqg_stats_waiting(stats))
		return;

	now = sched_clock();
	if (time_after64(now, stats->start_group_wait_time))
		blkg_stat_add(&stats->group_wait_time,
			      now - stats->start_group_wait_time);
	cfqg_stats_clear_waiting(stats);
}

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/* This should be called with the queue_lock held. */


static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg,
						 struct cfq_group *curr_cfqg)
{
	struct cfqg_stats *stats = &cfqg->stats;

	if (cfqg_stats_waiting(stats))
		return;
	if (cfqg == curr_cfqg)
		return;
	stats->start_group_wait_time = sched_clock();
	cfqg_stats_mark_waiting(stats);
}

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/* This should be called with the queue_lock held. */


static void cfqg_stats_end_empty_time(struct cfqg_stats *stats)
{
	unsigned long long now;

	if (!cfqg_stats_empty(stats))
		return;

	now = sched_clock();
	if (time_after64(now, stats->start_empty_time))
		blkg_stat_add(&stats->empty_time,
			      now - stats->start_empty_time);
	cfqg_stats_clear_empty(stats);
}

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static void cfqg_stats_update_dequeue(struct cfq_group *cfqg)
{
	blkg_stat_add(&cfqg->stats.dequeue, 1);
}

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static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg)
{
	struct cfqg_stats *stats = &cfqg->stats;

	if (blkg_rwstat_total(&stats->queued))
		return;

	/*
         * group is already marked empty. This can happen if cfqq got new
         * request in parent group and moved to this group while being added
         * to service tree. Just ignore the event and move on.
         */
	if (cfqg_stats_empty(stats))
		return;

	stats->start_empty_time = sched_clock();
	cfqg_stats_mark_empty(stats);
}

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static void cfqg_stats_update_idle_time(struct cfq_group *cfqg)
{
	struct cfqg_stats *stats = &cfqg->stats;

	if (cfqg_stats_idling(stats)) {
		unsigned long long now = sched_clock();

		if (time_after64(now, stats->start_idle_time))
			blkg_stat_add(&stats->idle_time,
				      now - stats->start_idle_time);
		cfqg_stats_clear_idling(stats);
	}
}

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static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg)
{
	struct cfqg_stats *stats = &cfqg->stats;

	BUG_ON(cfqg_stats_idling(stats));

	stats->start_idle_time = sched_clock();
	cfqg_stats_mark_idling(stats);
}

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static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg)
{
	struct cfqg_stats *stats = &cfqg->stats;

	blkg_stat_add(&stats->avg_queue_size_sum,
		      blkg_rwstat_total(&stats->queued));
	blkg_stat_add(&stats->avg_queue_size_samples, 1);
	cfqg_stats_update_group_wait_time(stats);
}

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#else	/* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */



static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { }
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static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { }
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static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { }
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static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { }
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static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { }
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static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { }
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static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { }

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#endif	/* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */

#ifdef CONFIG_CFQ_GROUP_IOSCHED



static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
{
	return pd ? container_of(pd, struct cfq_group, pd) : NULL;
}

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static struct cfq_group_data

*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
{
	return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL;
}

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static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
{
	return pd_to_blkg(&cfqg->pd);
}

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static struct blkcg_policy blkcg_policy_cfq;



static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg)
{
	return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq));
}

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static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg)
{
	return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq));
}

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static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg)
{
	struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent;

	return pblkg ? blkg_to_cfqg(pblkg) : NULL;
}

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static inline bool cfqg_is_descendant(struct cfq_group *cfqg,
				      struct cfq_group *ancestor)
{
	return cgroup_is_descendant(cfqg_to_blkg(cfqg)->blkcg->css.cgroup,
				    cfqg_to_blkg(ancestor)->blkcg->css.cgroup);
}

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static inline void cfqg_get(struct cfq_group *cfqg)
{
	return blkg_get(cfqg_to_blkg(cfqg));
}

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static inline void cfqg_put(struct cfq_group *cfqg)
{
	return blkg_put(cfqg_to_blkg(cfqg));
}

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#define cfq_log_cfqq(cfqd, cfqq, fmt, args...)	do {                    \
        char __pbuf[128];                                               \
                                                                        \
        blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf));  \
        blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \
                        cfq_cfqq_sync((cfqq)) ? 'S' : 'A',              \
                        cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
                          __pbuf, ##args);                              \
} while (0)


#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)	do {                    \
        char __pbuf[128];                                               \
                                                                        \
        blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf));          \
        blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args);    \
} while (0)



static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
					    struct cfq_group *curr_cfqg, int rw)
{
	blkg_rwstat_add(&cfqg->stats.queued, rw, 1);
	cfqg_stats_end_empty_time(&cfqg->stats);
	cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg);
}

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static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
			unsigned long time, unsigned long unaccounted_time)
{
	blkg_stat_add(&cfqg->stats.time, time);
#ifdef CONFIG_DEBUG_BLK_CGROUP
	blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time);
#endif
}

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static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw)
{
	blkg_rwstat_add(&cfqg->stats.queued, rw, -1);
}

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static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw)
{
	blkg_rwstat_add(&cfqg->stats.merged, rw, 1);
}

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static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
			uint64_t start_time, uint64_t io_start_time, int rw)
{
	struct cfqg_stats *stats = &cfqg->stats;
	unsigned long long now = sched_clock();

	if (time_after64(now, io_start_time))
		blkg_rwstat_add(&stats->service_time, rw, now - io_start_time);
	if (time_after64(io_start_time, start_time))
		blkg_rwstat_add(&stats->wait_time, rw,
				io_start_time - start_time);
}

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/* @stats = 0 */


static void cfqg_stats_reset(struct cfqg_stats *stats)
{
	/* queued stats shouldn't be cleared */
	blkg_rwstat_reset(&stats->merged);
	blkg_rwstat_reset(&stats->service_time);
	blkg_rwstat_reset(&stats->wait_time);
	blkg_stat_reset(&stats->time);
#ifdef CONFIG_DEBUG_BLK_CGROUP
	blkg_stat_reset(&stats->unaccounted_time);
	blkg_stat_reset(&stats->avg_queue_size_sum);
	blkg_stat_reset(&stats->avg_queue_size_samples);
	blkg_stat_reset(&stats->dequeue);
	blkg_stat_reset(&stats->group_wait_time);
	blkg_stat_reset(&stats->idle_time);
	blkg_stat_reset(&stats->empty_time);
#endif
}

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/* @to += @from */


static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from)
{
	/* queued stats shouldn't be cleared */
	blkg_rwstat_add_aux(&to->merged, &from->merged);
	blkg_rwstat_add_aux(&to->service_time, &from->service_time);
	blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
	blkg_stat_add_aux(&from->time, &from->time);
#ifdef CONFIG_DEBUG_BLK_CGROUP
	blkg_stat_add_aux(&to->unaccounted_time, &from->unaccounted_time);
	blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
	blkg_stat_add_aux(&to->avg_queue_size_samples, &from->avg_queue_size_samples);
	blkg_stat_add_aux(&to->dequeue, &from->dequeue);
	blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
	blkg_stat_add_aux(&to->idle_time, &from->idle_time);
	blkg_stat_add_aux(&to->empty_time, &from->empty_time);
#endif
}

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/*
 * Transfer @cfqg's stats to its parent's aux counts so that the ancestors'
 * recursive stats can still account for the amount used by this cfqg after
 * it's gone.
 */


static void cfqg_stats_xfer_dead(struct cfq_group *cfqg)
{
	struct cfq_group *parent = cfqg_parent(cfqg);

	lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock);

	if (unlikely(!parent))
		return;

	cfqg_stats_add_aux(&parent->stats, &cfqg->stats);
	cfqg_stats_reset(&cfqg->stats);
}

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#else	/* CONFIG_CFQ_GROUP_IOSCHED */



static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; }
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static inline bool cfqg_is_descendant(struct cfq_group *cfqg,
				      struct cfq_group *ancestor)
{
	return true;
}
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static inline void cfqg_get(struct cfq_group *cfqg) { }
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static inline void cfqg_put(struct cfq_group *cfqg) { }

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#define cfq_log_cfqq(cfqd, cfqq, fmt, args...)	\
	blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \
                        cfq_cfqq_sync((cfqq)) ? 'S' : 'A',              \
                        cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
                                ##args)

#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)		do {} while (0)



static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
			struct cfq_group *curr_cfqg, int rw) { }
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static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
			unsigned long time, unsigned long unaccounted_time) { }
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static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw) { }
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static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw) { }
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static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
			uint64_t start_time, uint64_t io_start_time, int rw) { }

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#endif	/* CONFIG_CFQ_GROUP_IOSCHED */


#define cfq_log(cfqd, fmt, args...)	\
	blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)

/* Traverses through cfq group service trees */

#define for_each_cfqg_st(cfqg, i, j, st) \
	for (i = 0; i <= IDLE_WORKLOAD; i++) \
                for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\
                        : &cfqg->service_tree_idle; \
                        (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \
                        (i == IDLE_WORKLOAD && j == 0); \
                        j++, st = i < IDLE_WORKLOAD ? \
                        &cfqg->service_trees[i][j]: NULL) \

static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd,
	struct cfq_ttime *ttime, bool group_idle)
{
	unsigned long slice;
	if (!sample_valid(ttime->ttime_samples))
		return false;
	if (group_idle)
		slice = cfqd->cfq_group_idle;
	else
		slice = cfqd->cfq_slice_idle;
	return ttime->ttime_mean > slice;
}



static inline bool iops_mode(struct cfq_data *cfqd)
{
	/*
         * If we are not idling on queues and it is a NCQ drive, parallel
         * execution of requests is on and measuring time is not possible
         * in most of the cases until and unless we drive shallower queue
         * depths and that becomes a performance bottleneck. In such cases
         * switch to start providing fairness in terms of number of IOs.
         */
	if (!cfqd->cfq_slice_idle && cfqd->hw_tag)
		return true;
	else
		return false;
}

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static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq)
{
	if (cfq_class_idle(cfqq))
		return IDLE_WORKLOAD;
	if (cfq_class_rt(cfqq))
		return RT_WORKLOAD;
	return BE_WORKLOAD;
}


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static enum wl_type_t cfqq_type(struct cfq_queue *cfqq)
{
	if (!cfq_cfqq_sync(cfqq))
		return ASYNC_WORKLOAD;
	if (!cfq_cfqq_idle_window(cfqq))
		return SYNC_NOIDLE_WORKLOAD;
	return SYNC_WORKLOAD;
}

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static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class,
					struct cfq_data *cfqd,
					struct cfq_group *cfqg)
{
	if (wl_class == IDLE_WORKLOAD)
		return cfqg->service_tree_idle.count;

	return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count +
		cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count +
		cfqg->service_trees[wl_class][SYNC_WORKLOAD].count;
}

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static inline int cfqg_busy_async_queues(struct cfq_data *cfqd,
					struct cfq_group *cfqg)
{
	return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count +
		cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
}

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static void cfq_dispatch_insert(struct request_queue *, struct request *);
static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync,
				       struct cfq_io_cq *cic, struct bio *bio);



static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq)
{
	/* cic->icq is the first member, %NULL will convert to %NULL */
	return container_of(icq, struct cfq_io_cq, icq);
}

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static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd,
					       struct io_context *ioc)
{
	if (ioc)
		return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue));
	return NULL;
}

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static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync)
{
	return cic->cfqq[is_sync];
}

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static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq,
				bool is_sync)
{
	cic->cfqq[is_sync] = cfqq;
}

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static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic)
{
	return cic->icq.q->elevator->elevator_data;
}

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/*
 * We regard a request as SYNC, if it's either a read or has the SYNC bit
 * set (in which case it could also be direct WRITE).
 */


static inline bool cfq_bio_sync(struct bio *bio)
{
	return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC);
}

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/*
 * scheduler run of queue, if there are requests pending and no one in the
 * driver that will restart queueing
 */


static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
{
	if (cfqd->busy_queues) {
		cfq_log(cfqd, "schedule dispatch");
		kblockd_schedule_work(&cfqd->unplug_work);
	}
}

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/*
 * Scale schedule slice based on io priority. Use the sync time slice only
 * if a queue is marked sync and has sync io queued. A sync queue with async
 * io only, should not get full sync slice length.
 */


static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync,
				 unsigned short prio)
{
	const int base_slice = cfqd->cfq_slice[sync];

	WARN_ON(prio >= IOPRIO_BE_NR);

	return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio));
}

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static inline int

cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio);
}

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/**
 * cfqg_scale_charge - scale disk time charge according to cfqg weight
 * @charge: disk time being charged
 * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT
 *
 * Scale @charge according to @vfraction, which is in range (0, 1].  The
 * scaling is inversely proportional.
 *
 * scaled = charge / vfraction
 *
 * The result is also in fixed point w/ CFQ_SERVICE_SHIFT.
 */


static inline u64 cfqg_scale_charge(unsigned long charge,
				    unsigned int vfraction)
{
	u64 c = charge << CFQ_SERVICE_SHIFT;	/* make it fixed point */

	/* charge / vfraction */
	c <<= CFQ_SERVICE_SHIFT;
	do_div(c, vfraction);
	return c;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
23
60.53%
1
50.00%
tejun heo
tejun heo
15
39.47%
1
50.00%
Total
38
100.00%
2
100.00%



static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime)
{
	s64 delta = (s64)(vdisktime - min_vdisktime);
	if (delta > 0)
		min_vdisktime = vdisktime;

	return min_vdisktime;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
38
100.00%
1
100.00%
Total
38
100.00%
1
100.00%



static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime)
{
	s64 delta = (s64)(vdisktime - min_vdisktime);
	if (delta < 0)
		min_vdisktime = vdisktime;

	return min_vdisktime;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
38
100.00%
1
100.00%
Total
38
100.00%
1
100.00%



static void update_min_vdisktime(struct cfq_rb_root *st)
{
	struct cfq_group *cfqg;

	if (st->left) {
		cfqg = rb_entry_cfqg(st->left);
		st->min_vdisktime = max_vdisktime(st->min_vdisktime,
						  cfqg->vdisktime);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
45
93.75%
1
50.00%
gui jianfeng
gui jianfeng
3
6.25%
1
50.00%
Total
48
100.00%
2
100.00%

/*
 * get averaged number of queues of RT/BE priority.
 * average is updated, with a formula that gives more weight to higher numbers,
 * to quickly follows sudden increases and decrease slowly
 */



static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd,
					struct cfq_group *cfqg, bool rt)
{
	unsigned min_q, max_q;
	unsigned mult  = cfq_hist_divisor - 1;
	unsigned round = cfq_hist_divisor / 2;
	unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg);

	min_q = min(cfqg->busy_queues_avg[rt], busy);
	max_q = max(cfqg->busy_queues_avg[rt], busy);
	cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) /
		cfq_hist_divisor;
	return cfqg->busy_queues_avg[rt];
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
corrado zoccolo
corrado zoccolo
82
77.36%
2
50.00%
vivek goyal
vivek goyal
13
12.26%
1
25.00%
jens axboe
jens axboe
11
10.38%
1
25.00%
Total
106
100.00%
4
100.00%


static inline unsigned

cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
	return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
21
75.00%
1
20.00%
jens axboe
jens axboe
3
10.71%
2
40.00%
tejun heo
tejun heo
3
10.71%
1
20.00%
justin teravest
justin teravest
1
3.57%
1
20.00%
Total
28
100.00%
5
100.00%


static inline unsigned

cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	unsigned slice = cfq_prio_to_slice(cfqd, cfqq);
	if (cfqd->cfq_latency) {
		/*
                 * interested queues (we consider only the ones with the same
                 * priority class in the cfq group)
                 */
		unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg,
						cfq_class_rt(cfqq));
		unsigned sync_slice = cfqd->cfq_slice[1];
		unsigned expect_latency = sync_slice * iq;
		unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg);

		if (expect_latency > group_slice) {
			unsigned base_low_slice = 2 * cfqd->cfq_slice_idle;
			/* scale low_slice according to IO priority
                         * and sync vs async */
			unsigned low_slice =
				min(slice, base_low_slice * slice / sync_slice);
			/* the adapted slice value is scaled to fit all iqs
                         * into the target latency */
			slice = max(slice * group_slice / expect_latency,
				    low_slice);
		}
	}
	return slice;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
corrado zoccolo
corrado zoccolo
84
64.12%
1
20.00%
vivek goyal
vivek goyal
23
17.56%
2
40.00%
jens axboe
jens axboe
19
14.50%
1
20.00%
li shaohua
li shaohua
5
3.82%
1
20.00%
Total
131
100.00%
5
100.00%


static inline void

cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq);

	cfqq->slice_start = jiffies;
	cfqq->slice_end = jiffies + slice;
	cfqq->allocated_slice = slice;
	cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
li shaohua
li shaohua
25
40.32%
1
14.29%
jens axboe
jens axboe
18
29.03%
2
28.57%
vivek goyal
vivek goyal
13
20.97%
3
42.86%
corrado zoccolo
corrado zoccolo
6
9.68%
1
14.29%
Total
62
100.00%
7
100.00%

/*
 * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end
 * isn't valid until the first request from the dispatch is activated
 * and the slice time set.
 */


static inline bool cfq_slice_used(struct cfq_queue *cfqq)
{
	if (cfq_cfqq_slice_new(cfqq))
		return false;
	if (time_before(jiffies, cfqq->slice_end))
		return false;

	return true;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
36
92.31%
2
66.67%
li shaohua
li shaohua
3
7.69%
1
33.33%
Total
39
100.00%
3
100.00%

/*
 * Lifted from AS - choose which of rq1 and rq2 that is best served now.
 * We choose the request that is closest to the head right now. Distance
 * behind the head is penalized and only allowed to a certain extent.
 */

static struct request *

cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last)
{
	sector_t s1, s2, d1 = 0, d2 = 0;
	unsigned long back_max;

#define CFQ_RQ1_WRAP	0x01 /* request 1 wraps */

#define CFQ_RQ2_WRAP	0x02 /* request 2 wraps */
	unsigned wrap = 0; /* bit mask: requests behind the disk head? */

	if (rq1 == NULL || rq1 == rq2)
		return rq2;
	if (rq2 == NULL)
		return rq1;

	if (rq_is_sync(rq1) != rq_is_sync(rq2))
		return rq_is_sync(rq1) ? rq1 : rq2;

	if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO)
		return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2;

	s1 = blk_rq_pos(rq1);
	s2 = blk_rq_pos(rq2);

	/*
         * by definition, 1KiB is 2 sectors
         */
	back_max = cfqd->cfq_back_max * 2;

	/*
         * Strict one way elevator _except_ in the case where we allow
         * short backward seeks which are biased as twice the cost of a
         * similar forward seek.
         */
	if (s1 >= last)
		d1 = s1 - last;
	else if (s1 + back_max >= last)
		d1 = (last - s1) * cfqd->cfq_back_penalty;
	else
		wrap |= CFQ_RQ1_WRAP;

	if (s2 >= last)
		d2 = s2 - last;
	else if (s2 + back_max >= last)
		d2 = (last - s2) * cfqd->cfq_back_penalty;
	else
		wrap |= CFQ_RQ2_WRAP;

	/* Found required data */

	/*
         * By doing switch() on the bit mask "wrap" we avoid having to
         * check two variables for all permutations: --> faster!
         */
	switch (wrap) {
	case 0: /* common case for CFQ: rq1 and rq2 not wrapped */
		if (d1 < d2)
			return rq1;
		else if (d2 < d1)
			return rq2;
		else {
			if (s1 >= s2)
				return rq1;
			else
				return rq2;
		}

	case CFQ_RQ2_WRAP:
		return rq1;
	case CFQ_RQ1_WRAP:
		return rq2;
	case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */
	default:
		/*
                 * Since both rqs are wrapped,
                 * start with the one that's further behind head
                 * (--> only *one* back seek required),
                 * since back seek takes more time than forward.
                 */
		if (s1 <= s2)
			return rq1;
		else
			return rq2;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
196
63.23%
6
50.00%
andreas mohr
andreas mohr
55
17.74%
1
8.33%
andrew morton
andrew morton
44
14.19%
1
8.33%
tejun heo
tejun heo
6
1.94%
1
8.33%
namhyung kim
namhyung kim
4
1.29%
1
8.33%
corrado zoccolo
corrado zoccolo
3
0.97%
1
8.33%
christoph hellwig
christoph hellwig
2
0.65%
1
8.33%
Total
310
100.00%
12
100.00%

/*
 * The below is leftmost cache rbtree addon
 */


static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
{
	/* Service tree is empty */
	if (!root->count)
		return NULL;

	if (!root->left)
		root->left = rb_first(&root->rb);

	if (root->left)
		return rb_entry(root->left, struct cfq_queue, rb_node);

	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
54
83.08%
2
66.67%
vivek goyal
vivek goyal
11
16.92%
1
33.33%
Total
65
100.00%
3
100.00%



static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root)
{
	if (!root->left)
		root->left = rb_first(&root->rb);

	if (root->left)
		return rb_entry_cfqg(root->left);

	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
49
100.00%
1
100.00%
Total
49
100.00%
1
100.00%



static void rb_erase_init(struct rb_node *n, struct rb_root *root)
{
	rb_erase(n, root);
	RB_CLEAR_NODE(n);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
28
100.00%
1
100.00%
Total
28
100.00%
1
100.00%



static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
{
	if (root->left == n)
		root->left = NULL;
	rb_erase_init(n, &root->rb);
	--root->count;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
40
88.89%
2
66.67%
corrado zoccolo
corrado zoccolo
5
11.11%
1
33.33%
Total
45
100.00%
3
100.00%

/*
 * would be nice to take fifo expire time into account as well
 */

static struct request *

cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
		  struct request *last)
{
	struct rb_node *rbnext = rb_next(&last->rb_node);
	struct rb_node *rbprev = rb_prev(&last->rb_node);
	struct request *next = NULL, *prev = NULL;

	BUG_ON(RB_EMPTY_NODE(&last->rb_node));

	if (rbprev)
		prev = rb_entry_rq(rbprev);

	if (rbnext)
		next = rb_entry_rq(rbnext);
	else {
		rbnext = rb_first(&cfqq->sort_list);
		if (rbnext && rbnext != &last->rb_node)
			next = rb_entry_rq(rbnext);
	}

	return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last));
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
69
49.29%
4
66.67%
vivek goyal
vivek goyal
43
30.71%
1
16.67%
andrew morton
andrew morton
28
20.00%
1
16.67%
Total
140
100.00%
6
100.00%



static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
				      struct cfq_queue *cfqq)
{
	/*
         * just an approximation, should be ok.
         */
	return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) -
		       cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
54
100.00%
1
100.00%
Total
54
100.00%
1
100.00%


static inline s64

cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg)
{
	return cfqg->vdisktime - st->min_vdisktime;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
26
100.00%
1
100.00%
Total
26
100.00%
1
100.00%


static void

__cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
{
	struct rb_node **node = &st->rb.rb_node;
	struct rb_node *parent = NULL;
	struct cfq_group *__cfqg;
	s64 key = cfqg_key(st, cfqg);
	int left = 1;

	while (*node != NULL) {
		parent = *node;
		__cfqg = rb_entry_cfqg(parent);

		if (key < cfqg_key(st, __cfqg))
			node = &parent->rb_left;
		else {
			node = &parent->rb_right;
			left = 0;
		}
	}

	if (left)
		st->left = &cfqg->rb_node;

	rb_link_node(&cfqg->rb_node, parent, node);
	rb_insert_color(&cfqg->rb_node, &st->rb);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
147
100.00%
1
100.00%
Total
147
100.00%
1
100.00%

/*
 * This has to be called only on activation of cfqg
 */

static void

cfq_update_group_weight(struct cfq_group *cfqg)
{
	if (cfqg->new_weight) {
		cfqg->weight = cfqg->new_weight;
		cfqg->new_weight = 0;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
justin teravest
justin teravest
27
81.82%
1
25.00%
tejun heo
tejun heo
3
9.09%
1
25.00%
vivek goyal
vivek goyal
2
6.06%
1
25.00%
toshiaki makita
toshiaki makita
1
3.03%
1
25.00%
Total
33
100.00%
4
100.00%


static void

cfq_update_group_leaf_weight(struct cfq_group *cfqg)
{
	BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));

	if (cfqg->new_leaf_weight) {
		cfqg->leaf_weight = cfqg->new_leaf_weight;
		cfqg->new_leaf_weight = 0;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
22
48.89%
1
33.33%
toshiaki makita
toshiaki makita
22
48.89%
1
33.33%
justin teravest
justin teravest
1
2.22%
1
33.33%
Total
45
100.00%
3
100.00%


static void

cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
{
	unsigned int vfr = 1 << CFQ_SERVICE_SHIFT;	/* start with 1 */
	struct cfq_group *pos = cfqg;
	struct cfq_group *parent;
	bool propagate;

	/* add to the service tree */
	BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));

	/*
         * Update leaf_weight.  We cannot update weight at this point
         * because cfqg might already have been activated and is
         * contributing its current weight to the parent's child_weight.
         */
	cfq_update_group_leaf_weight(cfqg);
	__cfq_group_service_tree_add(st, cfqg);

	/*
         * Activate @cfqg and calculate the portion of vfraction @cfqg is
         * entitled to.  vfraction is calculated by walking the tree
         * towards the root calculating the fraction it has at each level.
         * The compounded ratio is how much vfraction @cfqg owns.
         *
         * Start with the proportion tasks in this cfqg has against active
         * children cfqgs - its leaf_weight against children_weight.
         */
	propagate = !pos->nr_active++;
	pos->children_weight += pos->leaf_weight;
	vfr = vfr * pos->leaf_weight / pos->children_weight;

	/*
         * Compound ->weight walking up the tree.  Both activation and
         * vfraction calculation are done in the same loop.  Propagation
         * stops once an already activated node is met.  vfraction
         * calculation should always continue to the root.
         */
	while ((parent = cfqg_parent(pos))) {
		if (propagate) {
			cfq_update_group_weight(pos);
			propagate = !parent->nr_active++;
			parent->children_weight += pos->weight;
		}
		vfr = vfr * pos->weight / parent->children_weight;
		pos = parent;
	}

	cfqg->vfraction = max_t(unsigned, vfr, 1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
111
67.27%
3
42.86%
justin teravest
justin teravest
40
24.24%
1
14.29%
toshiaki makita
toshiaki makita
7
4.24%
2
28.57%
vivek goyal
vivek goyal
7
4.24%
1
14.29%
Total
165
100.00%
7
100.00%


static void

cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
	struct cfq_rb_root *st = &cfqd->grp_service_tree;
	struct cfq_group *__cfqg;
	struct rb_node *n;

	cfqg->nr_cfqq++;
	if (!RB_EMPTY_NODE(&cfqg->rb_node))
		return;

	/*
         * Currently put the group at the end. Later implement something
         * so that groups get lesser vtime based on their weights, so that
         * if group does not loose all if it was not continuously backlogged.
         */
	n = rb_last(&st->rb);
	if (n) {
		__cfqg = rb_entry_cfqg(n);
		cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY;
	} else
		cfqg->vdisktime = st->min_vdisktime;
	cfq_group_service_tree_add(st, cfqg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
73
70.87%
1
12.50%
jens axboe
jens axboe
11
10.68%
2
25.00%
justin teravest
justin teravest
7
6.80%
1
12.50%
gui jianfeng
gui jianfeng
6
5.83%
1
12.50%
andrew morton
andrew morton
4
3.88%
1
12.50%
lucas de marchi
lucas de marchi
1
0.97%
1
12.50%
corrado zoccolo
corrado zoccolo
1
0.97%
1
12.50%
Total
103
100.00%
8
100.00%


static void

cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg)
{
	struct cfq_group *pos = cfqg;
	bool propagate;

	/*
         * Undo activation from cfq_group_service_tree_add().  Deactivate
         * @cfqg and propagate deactivation upwards.
         */
	propagate = !--pos->nr_active;
	pos->children_weight -= pos->leaf_weight;

	while (propagate) {
		struct cfq_group *parent = cfqg_parent(pos);

		/* @pos has 0 nr_active at this point */
		WARN_ON_ONCE(pos->children_weight);
		pos->vfraction = 0;

		if (!parent)
			break;

		propagate = !--parent->nr_active;
		parent->children_weight -= pos->weight;
		pos = parent;
	}

	/* remove from the service tree */
	if (!RB_EMPTY_NODE(&cfqg->rb_node))
		cfq_rb_erase(&cfqg->rb_node, st);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
79
65.29%
3
50.00%
justin teravest
justin teravest
37
30.58%
1
16.67%
vivek goyal
vivek goyal
4
3.31%
1
16.67%
andrew morton
andrew morton
1
0.83%
1
16.67%
Total
121
100.00%
6
100.00%


static void

cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
	struct cfq_rb_root *st = &cfqd->grp_service_tree;

	BUG_ON(cfqg->nr_cfqq < 1);
	cfqg->nr_cfqq--;

	/* If there are other cfq queues under this group, don't delete it */
	if (cfqg->nr_cfqq)
		return;

	cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
	cfq_group_service_tree_del(st, cfqg);
	cfqg->saved_wl_slice = 0;
	cfqg_stats_update_dequeue(cfqg);
}

Contributors
Person
Tokens
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vivek goyal
vivek goyal
53
70.67%
6
46.15%
jens axboe
jens axboe
8
10.67%
3
23.08%
andrew morton
andrew morton
7
9.33%
1
7.69%
justin teravest
justin teravest
4
5.33%
1
7.69%
tejun heo
tejun heo
3
4.00%
2
15.38%
Total
75
100.00%
13
100.00%



static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq,
						unsigned int *unaccounted_time)
{
	unsigned int slice_used;

	/*
         * Queue got expired before even a single request completed or
         * got expired immediately after first request completion.
         */
	if (!cfqq->slice_start || cfqq->slice_start == jiffies) {
		/*
                 * Also charge the seek time incurred to the group, otherwise
                 * if there are mutiple queues in the group, each can dispatch
                 * a single request on seeky media and cause lots of seek time
                 * and group will never know it.
                 */
		slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start),
					1);
	} else {
		slice_used = jiffies - cfqq->slice_start;
		if (slice_used > cfqq->allocated_slice) {
			*unaccounted_time = slice_used - cfqq->allocated_slice;
			slice_used = cfqq->allocated_slice;
		}
		if (time_after(cfqq->slice_start, cfqq->dispatch_start))
			*unaccounted_time += cfqq->slice_start -
					cfqq->dispatch_start;
	}

	return slice_used;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
79
66.39%
2
66.67%
justin teravest
justin teravest
40
33.61%
1
33.33%
Total
119
100.00%
3
100.00%



static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
				struct cfq_queue *cfqq)
{
	struct cfq_rb_root *st = &cfqd->grp_service_tree;
	unsigned int used_sl, charge, unaccounted_sl = 0;
	int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg)
			- cfqg->service_tree_idle.count;
	unsigned int vfr;

	BUG_ON(nr_sync < 0);
	used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl);

	if (iops_mode(cfqd))
		charge = cfqq->slice_dispatch;
	else if (!cfq_cfqq_sync(cfqq) && !nr_sync)
		charge = cfqq->allocated_slice;

	/*
         * Can't update vdisktime while on service tree and cfqg->vfraction
         * is valid only while on it.  Cache vfr, leave the service tree,
         * update vdisktime and go back on.  The re-addition to the tree
         * will also update the weights as necessary.
         */
	vfr = cfqg->vfraction;
	cfq_group_service_tree_del(st, cfqg);
	cfqg->vdisktime += cfqg_scale_charge(charge, vfr);
	cfq_group_service_tree_add(st, cfqg);

	/* This group is being expired. Save the context */
	if (time_after(cfqd->workload_expires, jiffies)) {
		cfqg->saved_wl_slice = cfqd->workload_expires
						- jiffies;
		cfqg->saved_wl_type = cfqd->serving_wl_type;
		cfqg->saved_wl_class = cfqd->serving_wl_class;
	} else
		cfqg->saved_wl_slice = 0;

	cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
					st->min_vdisktime);
	cfq_log_cfqq(cfqq->cfqd, cfqq,
		     "sl_used=%u disp=%u charge=%u iops=%u sect=%lu",
		     used_sl, cfqq->slice_dispatch, charge,
		     iops_mode(cfqd), cfqq->nr_sectors);
	cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl);
	cfqg_stats_set_start_empty_time(cfqg);
}

Contributors
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vivek goyal
vivek goyal
217
85.77%
7
43.75%
tejun heo
tejun heo
19
7.51%
4
25.00%
justin teravest
justin teravest
13
5.14%
2
12.50%
divyesh shah
divyesh shah
2
0.79%
1
6.25%
jens axboe
jens axboe
1
0.40%
1
6.25%
joe perches
joe perches
1
0.40%
1
6.25%
Total
253
100.00%
16
100.00%

/**
 * cfq_init_cfqg_base - initialize base part of a cfq_group
 * @cfqg: cfq_group to initialize
 *
 * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED
 * is enabled or not.
 */


static void cfq_init_cfqg_base(struct cfq_group *cfqg)
{
	struct cfq_rb_root *st;
	int i, j;

	for_each_cfqg_st(cfqg, i, j, st)
		*st = CFQ_RB_ROOT;
	RB_CLEAR_NODE(&cfqg->rb_node);

	cfqg->ttime.last_end_request = jiffies;
}

Contributors
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tejun heo
tejun heo
52
100.00%
1
100.00%
Total
52
100.00%
1
100.00%

#ifdef CONFIG_CFQ_GROUP_IOSCHED
static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
			    bool on_dfl, bool reset_dev, bool is_leaf_weight);



static void cfqg_stats_exit(struct cfqg_stats *stats)
{
	blkg_rwstat_exit(&stats->merged);
	blkg_rwstat_exit(&stats->service_time);
	blkg_rwstat_exit(&stats->wait_time);
	blkg_rwstat_exit(&stats->queued);
	blkg_stat_exit(&stats->time);
#ifdef CONFIG_DEBUG_BLK_CGROUP
	blkg_stat_exit(&stats->unaccounted_time);
	blkg_stat_exit(&stats->avg_queue_size_sum);
	blkg_stat_exit(&stats->avg_queue_size_samples);
	blkg_stat_exit(&stats->dequeue);
	blkg_stat_exit(&stats->group_wait_time);
	blkg_stat_exit(&stats->idle_time);
	blkg_stat_exit(&stats->empty_time);
#endif
}

Contributors
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tejun heo
tejun heo
110
98.21%
1
50.00%
peter zijlstra
peter zijlstra
2
1.79%
1
50.00%
Total
112
100.00%
2
100.00%



static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp)
{
	if (blkg_rwstat_init(&stats->merged, gfp) ||
	    blkg_rwstat_init(&stats->service_time, gfp) ||
	    blkg_rwstat_init(&stats->wait_time, gfp) ||
	    blkg_rwstat_init(&stats->queued, gfp) ||
	    blkg_stat_init(&stats->time, gfp))
		goto err;

#ifdef CONFIG_DEBUG_BLK_CGROUP
	if (blkg_stat_init(&stats->unaccounted_time, gfp) ||
	    blkg_stat_init(&stats->avg_queue_size_sum, gfp) ||
	    blkg_stat_init(&stats->avg_queue_size_samples, gfp) ||
	    blkg_stat_init(&stats->dequeue, gfp) ||
	    blkg_stat_init(&stats->group_wait_time, gfp) ||
	    blkg_stat_init(&stats->idle_time, gfp) ||
	    blkg_stat_init(&stats->empty_time, gfp))
		goto err;
#endif
	return 0;
err:
	cfqg_stats_exit(stats);
	return -ENOMEM;
}

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peter zijlstra
peter zijlstra
98
60.12%
1
50.00%
tejun heo
tejun heo
65
39.88%
1
50.00%
Total
163
100.00%
2
100.00%



static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp)
{
	struct cfq_group_data *cgd;

	cgd = kzalloc(sizeof(*cgd), GFP_KERNEL);
	if (!cgd)
		return NULL;
	return &cgd->cpd;
}

Contributors
Person
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CommitProp
tejun heo
tejun heo
43
100.00%
1
100.00%
Total
43
100.00%
1
100.00%



static void cfq_cpd_init(struct blkcg_policy_data *cpd)
{
	struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
	unsigned int weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ?
			      CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;

	if (cpd_to_blkcg(cpd) == &blkcg_root)
		weight *= 2;

	cgd->weight = weight;
	cgd->leaf_weight = weight;
}

Contributors
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arianna avanzini
arianna avanzini
37
61.67%
1
25.00%
tejun heo
tejun heo
23
38.33%
3
75.00%
Total
60
100.00%
4
100.00%



static void cfq_cpd_free(struct blkcg_policy_data *cpd)
{
	kfree(cpd_to_cfqgd(cpd));
}

Contributors
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tejun heo
tejun heo
19
100.00%
1
100.00%
Total
19
100.00%
1
100.00%



static void cfq_cpd_bind(struct blkcg_policy_data *cpd)
{
	struct blkcg *blkcg = cpd_to_blkcg(cpd);
	bool on_dfl = cgroup_subsys_on_dfl(io_cgrp_subsys);
	unsigned int weight = on_dfl ? CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;

	if (blkcg == &blkcg_root)
		weight *= 2;

	WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, false));
	WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, true));
}

Contributors
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tejun heo
tejun heo
88
100.00%
2
100.00%
Total
88
100.00%
2
100.00%



static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
{
	struct cfq_group *cfqg;

	cfqg = kzalloc_node(sizeof(*cfqg), gfp, node);
	if (!cfqg)
		return NULL;

	cfq_init_cfqg_base(cfqg);
	if (cfqg_stats_init(&cfqg->stats, gfp)) {
		kfree(cfqg);
		return NULL;
	}

	return &cfqg->pd;
}

Contributors
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tejun heo
tejun heo
75
100.00%
3
100.00%
Total
75
100.00%
3
100.00%



static void cfq_pd_init(struct blkg_policy_data *pd)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);
	struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg);

	cfqg->weight = cgd->weight;
	cfqg->leaf_weight = cgd->leaf_weight;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
25
49.02%
6
66.67%
arianna avanzini
arianna avanzini
16
31.37%
1
11.11%
vivek goyal
vivek goyal
10
19.61%
2
22.22%
Total
51
100.00%
9
100.00%



static void cfq_pd_offline(struct blkg_policy_data *pd)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);
	int i;

	for (i = 0; i < IOPRIO_BE_NR; i++) {
		if (cfqg->async_cfqq[0][i])
			cfq_put_queue(cfqg->async_cfqq[0][i]);
		if (cfqg->async_cfqq[1][i])
			cfq_put_queue(cfqg->async_cfqq[1][i]);
	}

	if (cfqg->async_idle_cfqq)
		cfq_put_queue(cfqg->async_idle_cfqq);

	/*
         * @blkg is going offline and will be ignored by
         * blkg_[rw]stat_recursive_sum().  Transfer stats to the parent so
         * that they don't get lost.  If IOs complete after this point, the
         * stats for them will be lost.  Oh well...
         */
	cfqg_stats_xfer_dead(cfqg);
}

Contributors
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Tokens
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CommitProp
tejun heo
tejun heo
108
100.00%
4
100.00%
Total
108
100.00%
4
100.00%



static void cfq_pd_free(struct blkg_policy_data *pd)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);

	cfqg_stats_exit(&cfqg->stats);
	return kfree(cfqg);
}

Contributors
Person
Tokens
Prop
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CommitProp
tejun heo
tejun heo
35
100.00%
2
100.00%
Total
35
100.00%
2
100.00%



static void cfq_pd_reset_stats(struct blkg_policy_data *pd)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);

	cfqg_stats_reset(&cfqg->stats);
}

Contributors
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tejun heo
tejun heo
29
100.00%
2
100.00%
Total
29
100.00%
2
100.00%



static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
					 struct blkcg *blkcg)
{
	struct blkcg_gq *blkg;

	blkg = blkg_lookup(blkcg, cfqd->queue);
	if (likely(blkg))
		return blkg_to_cfqg(blkg);
	return NULL;
}

Contributors
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tejun heo
tejun heo
50
100.00%
3
100.00%
Total
50
100.00%
3
100.00%



static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
{
	cfqq->cfqg = cfqg;
	/* cfqq reference on cfqg */
	cfqg_get(cfqg);
}

Contributors
Person
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tejun heo
tejun heo
28
100.00%
1
100.00%
Total
28
100.00%
1
100.00%



static u64 cfqg_prfill_weight_device(struct seq_file *sf,
				     struct blkg_policy_data *pd, int off)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);

	if (!cfqg->dev_weight)
		return 0;
	return __blkg_prfill_u64(sf, pd, cfqg->dev_weight);
}

Contributors
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tejun heo
tejun heo
51
100.00%
3
100.00%
Total
51
100.00%
3
100.00%



static int cfqg_print_weight_device(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_weight_device, &blkcg_policy_cfq,
			  0, false);
	return 0;
}

Contributors
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tejun heo
tejun heo
40
100.00%
6
100.00%
Total
40
100.00%
6
100.00%



static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf,
					  struct blkg_policy_data *pd, int off)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);

	if (!cfqg->dev_leaf_weight)
		return 0;
	return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight);
}

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tejun heo
tejun heo
51
100.00%
2
100.00%
Total
51
100.00%
2
100.00%



static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq,
			  0, false);
	return 0;
}

Contributors
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tejun heo
tejun heo
40
100.00%
3
100.00%
Total
40
100.00%
3
100.00%



static int cfq_print_weight(struct seq_file *sf, void *v)
{
	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
	unsigned int val = 0;

	if (cgd)
		val = cgd->weight;

	seq_printf(sf, "%u\n", val);
	return 0;
}

Contributors
Person
Tokens
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CommitProp
jens axboe
jens axboe
27
40.91%
1
20.00%
tejun heo
tejun heo
23
34.85%
3
60.00%
arianna avanzini
arianna avanzini
16
24.24%
1
20.00%
Total
66
100.00%
5
100.00%



static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
{
	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
	unsigned int val = 0;

	if (cgd)
		val = cgd->leaf_weight;

	seq_printf(sf, "%u\n", val);
	return 0;
}

Contributors
Person
Tokens
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Commits
CommitProp
jens axboe
jens axboe
27
40.91%
1
20.00%
tejun heo
tejun heo
23
34.85%
3
60.00%
arianna avanzini
arianna avanzini
16
24.24%
1
20.00%
Total
66
100.00%
5
100.00%



static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
					char *buf, size_t nbytes, loff_t off,
					bool on_dfl, bool is_leaf_weight)
{
	unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
	unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
	struct blkcg *blkcg = css_to_blkcg(of_css(of));
	struct blkg_conf_ctx ctx;
	struct cfq_group *cfqg;
	struct cfq_group_data *cfqgd;
	int ret;
	u64 v;

	ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx);
	if (ret)
		return ret;

	if (sscanf(ctx.body, "%llu", &v) == 1) {
		/* require "default" on dfl */
		ret = -ERANGE;
		if (!v && on_dfl)
			goto out_finish;
	} else if (!strcmp(strim(ctx.body), "default")) {
		v = 0;
	} else {
		ret = -EINVAL;
		goto out_finish;
	}

	cfqg = blkg_to_cfqg(ctx.blkg);
	cfqgd = blkcg_to_cfqgd(blkcg);

	ret = -ERANGE;
	if (!v || (v >= min && v <= max)) {
		if (!is_leaf_weight) {
			cfqg->dev_weight = v;
			cfqg->new_weight = v ?: cfqgd->weight;
		} else {
			cfqg->dev_leaf_weight = v;
			cfqg->new_leaf_weight = v ?: cfqgd->leaf_weight;
		}
		ret = 0;
	}
out_finish:
	blkg_conf_finish(&ctx);
	return ret ?: nbytes;
}

Contributors
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tejun heo
tejun heo
250
92.94%
12
85.71%
arianna avanzini
arianna avanzini
16
5.95%
1
7.14%
jens axboe
jens axboe
3
1.12%
1
7.14%
Total
269
100.00%
14
100.00%



static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of,
				      char *buf, size_t nbytes, loff_t off)
{
	return __cfqg_set_weight_device(of, buf, nbytes, off, false, false);
}

Contributors
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tejun heo
tejun heo
37
100.00%
4
100.00%
Total
37
100.00%
4
100.00%



static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of,
					   char *buf, size_t nbytes, loff_t off)
{
	return __cfqg_set_weight_device(of, buf, nbytes, off, false, true);
}

Contributors
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tejun heo
tejun heo
37
100.00%
3
100.00%
Total
37
100.00%
3
100.00%



static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
			    bool on_dfl, bool reset_dev, bool is_leaf_weight)
{
	unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
	unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
	struct blkcg *blkcg = css_to_blkcg(css);
	struct blkcg_gq *blkg;
	struct cfq_group_data *cfqgd;
	int ret = 0;

	if (val < min || val > max)
		return -ERANGE;

	spin_lock_irq(&blkcg->lock);
	cfqgd = blkcg_to_cfqgd(blkcg);
	if (!cfqgd) {
		ret = -EINVAL;
		goto out;
	}

	if (!is_leaf_weight)
		cfqgd->weight = val;
	else
		cfqgd->leaf_weight = val;

	hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
		struct cfq_group *cfqg = blkg_to_cfqg(blkg);

		if (!cfqg)
			continue;

		if (!is_leaf_weight) {
			if (reset_dev)
				cfqg->dev_weight = 0;
			if (!cfqg->dev_weight)
				cfqg->new_weight = cfqgd->weight;
		} else {
			if (reset_dev)
				cfqg->dev_leaf_weight = 0;
			if (!cfqg->dev_leaf_weight)
				cfqg->new_leaf_weight = cfqgd->leaf_weight;
		}
	}

out:
	spin_unlock_irq(&blkcg->lock);
	return ret;
}

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tejun heo
tejun heo
186
81.22%
6
75.00%
jens axboe
jens axboe
23
10.04%
1
12.50%
arianna avanzini
arianna avanzini
20
8.73%
1
12.50%
Total
229
100.00%
8
100.00%



static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
			  u64 val)
{
	return __cfq_set_weight(css, val, false, false, false);
}

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static int cfq_set_leaf_weight(struct cgroup_subsys_state *css,
			       struct cftype *cft, u64 val)
{
	return __cfq_set_weight(css, val, false, false, true);
}

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static int cfqg_print_stat(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
			  &blkcg_policy_cfq, seq_cft(sf)->private, false);
	return 0;
}

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static int cfqg_print_rwstat(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat,
			  &blkcg_policy_cfq, seq_cft(sf)->private, true);
	return 0;
}

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45
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static u64 cfqg_prfill_stat_recursive(struct seq_file *sf,
				      struct blkg_policy_data *pd, int off)
{
	u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd),
					  &blkcg_policy_cfq, off);
	return __blkg_prfill_u64(sf, pd, sum);
}

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45
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static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf,
					struct blkg_policy_data *pd, int off)
{
	struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd),
							&blkcg_policy_cfq, off);
	return __blkg_prfill_rwstat(sf, pd, &sum);
}

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100.00%



static int cfqg_print_stat_recursive(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_stat_recursive, &blkcg_policy_cfq,
			  seq_cft(sf)->private, false);
	return 0;
}

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45
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100.00%



static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq,
			  seq_cft(sf)->private, true);
	return 0;
}

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100.00%



static u64 cfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd,
			       int off)
{
	u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes);

	return __blkg_prfill_u64(sf, pd, sum >> 9);
}

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static int cfqg_print_stat_sectors(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_sectors, &blkcg_policy_cfq, 0, false);
	return 0;
}

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40
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100.00%



static u64 cfqg_prfill_sectors_recursive(struct seq_file *sf,
					 struct blkg_policy_data *pd, int off)
{
	struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL,
					offsetof(struct blkcg_gq, stat_bytes));
	u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
		atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);

	return __blkg_prfill_u64(sf, pd, sum >> 9);
}

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100.00%



static int cfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_sectors_recursive, &blkcg_policy_cfq, 0,
			  false);
	return 0;
}

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#ifdef CONFIG_DEBUG_BLK_CGROUP


static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf,
				      struct blkg_policy_data *pd, int off)
{
	struct cfq_group *cfqg = pd_to_cfqg(pd);
	u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples);
	u64 v = 0;

	if (samples) {
		v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum);
		v = div64_u64(v, samples);
	}
	__blkg_prfill_u64(sf, pd, v);
	return 0;
}

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tejun heo
83
96.51%
3
75.00%
anatol pomozov
anatol pomozov
3
3.49%
1
25.00%
Total
86
100.00%
4
100.00%

/* print avg_queue_size */


static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v)
{
	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
			  cfqg_prfill_avg_queue_size, &blkcg_policy_cfq,
			  0, false);
	return 0;
}
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#endif	/* CONFIG_DEBUG_BLK_CGROUP */


static struct cftype cfq_blkcg_legacy_files[] = {
	/* on root, weight is mapped to leaf_weight */
	{
		.name = "weight_device",
		.flags = CFTYPE_ONLY_ON_ROOT,
		.seq_show = cfqg_print_leaf_weight_device,
		.write = cfqg_set_leaf_weight_device,
        },
	{
		.name = "weight",
		.flags = CFTYPE_ONLY_ON_ROOT,
		.seq_show = cfq_print_leaf_weight,
		.write_u64 = cfq_set_leaf_weight,
        },

	/* no such mapping necessary for !roots */
	{
		.name = "weight_device",
		.flags = CFTYPE_NOT_ON_ROOT,
		.seq_show = cfqg_print_weight_device,
		.write = cfqg_set_weight_device,
        },
	{
		.name = "weight",
		.flags = CFTYPE_NOT_ON_ROOT,
		.seq_show = cfq_print_weight,
		.write_u64 = cfq_set_weight,
        },

	{
		.name = "leaf_weight_device",
		.seq_show = cfqg_print_leaf_weight_device,
		.write = cfqg_set_leaf_weight_device,
        },
	{
		.name = "leaf_weight",
		.seq_show = cfq_print_leaf_weight,
		.write_u64 = cfq_set_leaf_weight,
        },

	/* statistics, covers only the tasks in the cfqg */
	{
		.name = "time",
		.private = offsetof(struct cfq_group, stats.time),
		.seq_show = cfqg_print_stat,
        },
	{
		.name = "sectors",
		.seq_show = cfqg_print_stat_sectors,
        },
	{
		.name = "io_service_bytes",
		.private = (unsigned long)&blkcg_policy_cfq,
		.seq_show = blkg_print_stat_bytes,
        },
	{
		.name = "io_serviced",
		.private = (unsigned long)&blkcg_policy_cfq,
		.seq_show = blkg_print_stat_ios,
        },
	{
		.name = "io_service_time",
		.private = offsetof(struct cfq_group, stats.service_time),
		.seq_show = cfqg_print_rwstat,
        },
	{
		.name = "io_wait_time",
		.private = offsetof(struct cfq_group, stats.wait_time),
		.seq_show = cfqg_print_rwstat,
        },
	{
		.name = "io_merged",
		.private = offsetof(struct cfq_group, stats.merged),
		.seq_show = cfqg_print_rwstat,
        },
	{
		.name = "io_queued",
		.private = offsetof(struct cfq_group, stats.queued),
		.seq_show = cfqg_print_rwstat,
        },

	/* the same statictics which cover the cfqg and its descendants */
	{
		.name = "time_recursive",
		.private = offsetof(struct cfq_group, stats.time),
		.seq_show = cfqg_print_stat_recursive,
        },
	{
		.name = "sectors_recursive",
		.seq_show = cfqg_print_stat_sectors_recursive,
        },
	{
		.name = "io_service_bytes_recursive",
		.private = (unsigned long)&blkcg_policy_cfq,
		.seq_show = blkg_print_stat_bytes_recursive,
        },
	{
		.name = "io_serviced_recursive",
		.private = (unsigned long)&blkcg_policy_cfq,
		.seq_show = blkg_print_stat_ios_recursive,
        },
	{
		.name = "io_service_time_recursive",
		.private = offsetof(struct cfq_group, stats.service_time),
		.seq_show = cfqg_print_rwstat_recursive,
        },
	{
		.name = "io_wait_time_recursive",
		.private = offsetof(struct cfq_group, stats.wait_time),
		.seq_show = cfqg_print_rwstat_recursive,
        },
	{
		.name = "io_merged_recursive",
		.private = offsetof(struct cfq_group, stats.merged),
		.seq_show = cfqg_print_rwstat_recursive,
        },
	{
		.name = "io_queued_recursive",
		.private = offsetof(struct cfq_group, stats.queued),
		.seq_show = cfqg_print_rwstat_recursive,
        },
#ifdef CONFIG_DEBUG_BLK_CGROUP
	{
		.name = "avg_queue_size",
		.seq_show = cfqg_print_avg_queue_size,
        },
	{
		.name = "group_wait_time",
		.private = offsetof(struct cfq_group, stats.group_wait_time),
		.seq_show = cfqg_print_stat,
        },
	{
		.name = "idle_time",
		.private = offsetof(struct cfq_group, stats.idle_time),
		.seq_show = cfqg_print_stat,
        },
	{
		.name = "empty_time",
		.private = offsetof(struct cfq_group, stats.empty_time),
		.seq_show = cfqg_print_stat,
        },
	{
		.name = "dequeue",
		.private = offsetof(struct cfq_group, stats.dequeue),
		.seq_show = cfqg_print_stat,
        },
	{
		.name = "unaccounted_time",
		.private = offsetof(struct cfq_group, stats.unaccounted_time),
		.seq_show = cfqg_print_stat,
        },
#endif	/* CONFIG_DEBUG_BLK_CGROUP */
	{ }	/* terminate */
};



static int cfq_print_weight_on_dfl(struct seq_file *sf, void *v)
{
	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);

	seq_printf(sf, "default %u\n", cgd->weight);
	blkcg_print_blkgs(sf, blkcg, cfqg_prfill_weight_device,
			  &blkcg_policy_cfq, 0, false);
	return 0;
}

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static ssize_t cfq_set_weight_on_dfl(struct kernfs_open_file *of,
				     char *buf, size_t nbytes, loff_t off)
{
	char *endp;
	int ret;
	u64 v;

	buf = strim(buf);

	/* "WEIGHT" or "default WEIGHT" sets the default weight */
	v = simple_strtoull(buf, &endp, 0);
	if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) {
		ret = __cfq_set_weight(of_css(of), v, true, false, false);
		return ret ?: nbytes;
	}

	/* "MAJ:MIN WEIGHT" */
	return __cfqg_set_weight_device(of, buf, nbytes, off, true, false);
}

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static struct cftype cfq_blkcg_files[] = {
	{
		.name = "weight",
		.flags = CFTYPE_NOT_ON_ROOT,
		.seq_show = cfq_print_weight_on_dfl,
		.write = cfq_set_weight_on_dfl,
        },
	{ }	/* terminate */
};

#else /* GROUP_IOSCHED */


static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
					 struct blkcg *blkcg)
{
	return cfqd->root_group;
}

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6
26.09%
3
75.00%
Total
23
100.00%
4
100.00%


static inline void

cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) {
	cfqq->cfqg = cfqg;
}

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#endif /* GROUP_IOSCHED */

/*
 * The cfqd->service_trees holds all pending cfq_queue's that have
 * requests waiting to be processed. It is sorted in the order that
 * we will service the queues.
 */


static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
				 bool add_front)
{
	struct rb_node **p, *parent;
	struct cfq_queue *__cfqq;
	unsigned long rb_key;
	struct cfq_rb_root *st;
	int left;
	int new_cfqq = 1;

	st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq));
	if (cfq_class_idle(cfqq)) {
		rb_key = CFQ_IDLE_DELAY;
		parent = rb_last(&st->rb);
		if (parent && parent != &cfqq->rb_node) {
			__cfqq = rb_entry(parent, struct cfq_queue, rb_node);
			rb_key += __cfqq->rb_key;
		} else
			rb_key += jiffies;
	} else if (!add_front) {
		/*
                 * Get our rb key offset. Subtract any residual slice
                 * value carried from last service. A negative resid
                 * count indicates slice overrun, and this should position
                 * the next service time further away in the tree.
                 */
		rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies;
		rb_key -= cfqq->slice_resid;
		cfqq->slice_resid = 0;
	} else {
		rb_key = -HZ;
		__cfqq = cfq_rb_first(st);
		rb_key += __cfqq ? __cfqq->rb_key : jiffies;
	}

	if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
		new_cfqq = 0;
		/*
                 * same position, nothing more to do
                 */
		if (rb_key == cfqq->rb_key && cfqq->service_tree == st)
			return;

		cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
		cfqq->service_tree = NULL;
	}

	left = 1;
	parent = NULL;
	cfqq->service_tree = st;
	p = &st->rb.rb_node;
	while (*p) {
		parent = *p;
		__cfqq = rb_entry(parent, struct cfq_queue, rb_node);

		/*
                 * sort by key, that represents service time.
                 */
		if (time_before(rb_key, __cfqq->rb_key))
			p = &parent->rb_left;
		else {
			p = &parent->rb_right;
			left = 0;
		}
	}

	if (left)
		st->left = &cfqq->rb_node;

	cfqq->rb_key = rb_key;
	rb_link_node(&cfqq->rb_node, parent, p);
	rb_insert_color(&cfqq->rb_node, &st->rb);
	st->count++;
	if (add_front || !new_cfqq)
		return;
	cfq_group_notify_queue_add(cfqd, cfqq->cfqg);
}

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270
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52.17%
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corrado zoccolo
66
17.28%
4
17.39%
vivek goyal
vivek goyal
45
11.78%
6
26.09%
justin teravest
justin teravest
1
0.26%
1
4.35%
Total
382
100.00%
23
100.00%


static struct cfq_queue *

cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root,
		     sector_t sector, struct rb_node **ret_parent,
		     struct rb_node ***rb_link)
{
	struct rb_node **p, *parent;
	struct cfq_queue *cfqq = NULL;

	parent = NULL;
	p = &root->rb_node;
	while (*p) {
		struct rb_node **n;

		parent = *p;
		cfqq = rb_entry(parent, struct cfq_queue, p_node);

		/*
                 * Sort strictly based on sector.  Smallest to the left,
                 * largest to the right.
                 */
		if (sector > blk_rq_pos(cfqq->next_rq))
			n = &(*p)->rb_right;
		else if (sector < blk_rq_pos(cfqq->next_rq))
			n = &(*p)->rb_left;
		else
			break;
		p = n;
		cfqq = NULL;
	}

	*ret_parent = parent;
	if (rb_link)
		*rb_link = p;
	return cfqq;
}

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66.67%
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andrew morton
6
3.70%
1
11.11%
divyesh shah
divyesh shah
6
3.70%
1
11.11%
tejun heo
tejun heo
6
3.70%
1
11.11%
Total
162
100.00%
9
100.00%



static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	struct rb_node **p, *parent;
	struct cfq_queue *__cfqq;

	if (cfqq->p_root) {
		rb_erase(&cfqq->p_node, cfqq->p_root);
		cfqq->p_root = NULL;
	}

	if (cfq_class_idle(cfqq))
		return;
	if (!cfqq->next_rq)
		return;

	cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio];
	__cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root,
				      blk_rq_pos(cfqq->next_rq), &parent, &p);
	if (!__cfqq) {
		rb_link_node(&cfqq->p_node, parent, p);
		rb_insert_color(&cfqq->p_node, cfqq->p_root);
	} else
		cfqq->p_root = NULL;
}

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8
72.73%
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divyesh shah
4
2.70%
1
9.09%
andrew morton
andrew morton
4
2.70%
1
9.09%
tejun heo
tejun heo
3
2.03%
1
9.09%
Total
148
100.00%
11
100.00%

/*
 * Update cfqq's position in the service tree.
 */


static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	/*
         * Resorting requires the cfqq to be on the RR list already.
         */
	if (cfq_cfqq_on_rr(cfqq)) {
		cfq_service_tree_add(cfqd, cfqq, 0);
		cfq_prio_tree_add(cfqd, cfqq);
	}
}

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andrew morton
11
26.19%
1
20.00%
Total
42
100.00%
5
100.00%

/*
 * add to busy list of queues for service, trying to be fair in ordering
 * the pending list according to last request service
 */


static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	cfq_log_cfqq(cfqd, cfqq, "add_to_rr");
	BUG_ON(cfq_cfqq_on_rr(cfqq));
	cfq_mark_cfqq_on_rr(cfqq);
	cfqd->busy_queues++;
	if (cfq_cfqq_sync(cfqq))
		cfqd->busy_sync_queues++;

	cfq_resort_rr_list(cfqd, cfqq);
}

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71.43%
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12
19.35%
1
14.29%
andrew morton
andrew morton
7
11.29%
1
14.29%
Total
62
100.00%
7
100.00%

/*
 * Called when the cfqq no longer has requests pending, remove it from
 * the service tree.
 */


static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	cfq_log_cfqq(cfqd, cfqq, "del_from_rr");
	BUG_ON(!cfq_cfqq_on_rr(cfqq));
	cfq_clear_cfqq_on_rr(cfqq);

	if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
		cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
		cfqq->service_tree = NULL;
	}
	if (cfqq->p_root) {
		rb_erase(&cfqq->p_node, cfqq->p_root);
		cfqq->p_root = NULL;
	}

	cfq_group_notify_queue_del(cfqd, cfqq->cfqg);
	BUG_ON(!cfqd->busy_queues);
	cfqd->busy_queues--;
	if (cfq_cfqq_sync(cfqq))
		cfqd->busy_sync_queues--;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
93
71.54%
4
44.44%
li shaohua
li shaohua
12
9.23%
1
11.11%
corrado zoccolo
corrado zoccolo
9
6.92%
1
11.11%
vivek goyal
vivek goyal
8
6.15%
1
11.11%
andrew morton
andrew morton
7
5.38%
1
11.11%
justin teravest
justin teravest
1
0.77%
1
11.11%
Total
130
100.00%
9
100.00%

/*
 * rb tree support functions
 */


static void cfq_del_rq_rb(struct request *rq)
{
	struct cfq_queue *cfqq = RQ_CFQQ(rq);
	const int sync = rq_is_sync(rq);

	BUG_ON(!cfqq->queued[sync]);
	cfqq->queued[sync]--;

	elv_rb_del(&cfqq->sort_list, rq);

	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) {
		/*
                 * Queue will be deleted from service tree when we actually
                 * expire it later. Right now just remove it from prio tree
                 * as it is empty.
                 */
		if (cfqq->p_root) {
			rb_erase(&cfqq->p_node, cfqq->p_root);
			cfqq->p_root = NULL;
		}
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
79
76.70%
1
50.00%
vivek goyal
vivek goyal
24
23.30%
1
50.00%
Total
103
100.00%
2
100.00%



static void cfq_add_rq_rb(struct request *rq)
{
	struct cfq_queue *cfqq = RQ_CFQQ(rq);
	struct cfq_data *cfqd = cfqq->cfqd;
	struct request *prev;

	cfqq->queued[rq_is_sync(rq)]++;

	elv_rb_add(&cfqq->sort_list, rq);

	if (!cfq_cfqq_on_rr(cfqq))
		cfq_add_cfqq_rr(cfqd, cfqq);

	/*
         * check if this request is a better next-serve candidate
         */
	prev = cfqq->next_rq;
	cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position);

	/*
         * adjust priority tree position, if ->next_rq changes
         */
	if (prev != cfqq->next_rq)
		cfq_prio_tree_add(cfqd, cfqq);

	BUG_ON(!cfqq->next_rq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
104
85.95%
7
77.78%
andrew morton
andrew morton
13
10.74%
1
11.11%
corrado zoccolo
corrado zoccolo
4
3.31%
1
11.11%
Total
121
100.00%
9
100.00%



static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
{
	elv_rb_del(&cfqq->sort_list, rq);
	cfqq->queued[rq_is_sync(rq)]--;
	cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
	cfq_add_rq_rb(rq);
	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group,
				 rq->cmd_flags);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
35
48.61%
5
45.45%
divyesh shah
divyesh shah
13
18.06%
1
9.09%
tejun heo
tejun heo
9
12.50%
3
27.27%
vivek goyal
vivek goyal
8
11.11%
1
9.09%
andrew morton
andrew morton
7
9.72%
1
9.09%
Total
72
100.00%
11
100.00%


static struct request *

cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
{
	struct task_struct *tsk = current;
	struct cfq_io_cq *cic;
	struct cfq_queue *cfqq;

	cic = cfq_cic_lookup(cfqd, tsk->io_context);
	if (!cic)
		return NULL;

	cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio));
	if (cfqq)
		return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio));

	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
33
37.93%
5
55.56%
vasily tarasov
vasily tarasov
25
28.74%
1
11.11%
andrew morton
andrew morton
24
27.59%
1
11.11%
kent overstreet
kent overstreet
4
4.60%
1
11.11%
tejun heo
tejun heo
1
1.15%
1
11.11%
Total
87
100.00%
9
100.00%



static void cfq_activate_request(struct request_queue *q, struct request *rq)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;

	cfqd->rq_in_driver++;
	cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d",
						cfqd->rq_in_driver);

	cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
47
75.81%
7
70.00%
andrew morton
andrew morton
7
11.29%
1
10.00%
tejun heo
tejun heo
6
9.68%
1
10.00%
corrado zoccolo
corrado zoccolo
2
3.23%
1
10.00%
Total
62
100.00%
10
100.00%



static void cfq_deactivate_request(struct request_queue *q, struct request *rq)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;

	WARN_ON(!cfqd->rq_in_driver);
	cfqd->rq_in_driver--;
	cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d",
						cfqd->rq_in_driver);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
45
80.36%
6
75.00%
andrew morton
andrew morton
9
16.07%
1
12.50%
corrado zoccolo
corrado zoccolo
2
3.57%
1
12.50%
Total
56
100.00%
8
100.00%



static void cfq_remove_request(struct request *rq)
{
	struct cfq_queue *cfqq = RQ_CFQQ(rq);

	if (cfqq->next_rq == rq)
		cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq);

	list_del_init(&rq->queuelist);
	cfq_del_rq_rb(rq);

	cfqq->cfqd->rq_queued--;
	cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
	if (rq->cmd_flags & REQ_PRIO) {
		WARN_ON(!cfqq->prio_pending);
		cfqq->prio_pending--;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
71
71.72%
8
53.33%
aaron carroll
aaron carroll
7
7.07%
1
6.67%
andrew morton
andrew morton
6
6.06%
1
6.67%
vivek goyal
vivek goyal
4
4.04%
1
6.67%
divyesh shah
divyesh shah
4
4.04%
1
6.67%
tejun heo
tejun heo
4
4.04%
2
13.33%
christoph hellwig
christoph hellwig
3
3.03%
1
6.67%
Total
99
100.00%
15
100.00%



static int cfq_merge(struct request_queue *q, struct request **req,
		     struct bio *bio)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct request *__rq;

	__rq = cfq_find_rq_fmerge(cfqd, bio);
	if (__rq && elv_rq_merge_ok(__rq, bio)) {
		*req = __rq;
		return ELEVATOR_FRONT_MERGE;
	}

	return ELEVATOR_NO_MERGE;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
61
85.92%
6
85.71%
andrew morton
andrew morton
10
14.08%
1
14.29%
Total
71
100.00%
7
100.00%



static void cfq_merged_request(struct request_queue *q, struct request *req,
			       int type)
{
	if (type == ELEVATOR_FRONT_MERGE) {
		struct cfq_queue *cfqq = RQ_CFQQ(req);

		cfq_reposition_rq_rb(cfqq, req);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
27
61.36%
4
80.00%
andrew morton
andrew morton
17
38.64%
1
20.00%
Total
44
100.00%
5
100.00%



static void cfq_bio_merged(struct request_queue *q, struct request *req,
				struct bio *bio)
{
	cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_rw);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
divyesh shah
divyesh shah
25
75.76%
1
25.00%
vivek goyal
vivek goyal
4
12.12%
1
25.00%
tejun heo
tejun heo
4
12.12%
2
50.00%
Total
33
100.00%
4
100.00%


static void

cfq_merged_requests(struct request_queue *q, struct request *rq,
		    struct request *next)
{
	struct cfq_queue *cfqq = RQ_CFQQ(rq);
	struct cfq_data *cfqd = q->elevator->elevator_data;

	/*
         * reposition in fifo if next is older than rq
         */
	if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) &&
	    time_before(next->fifo_time, rq->fifo_time) &&
	    cfqq == RQ_CFQQ(next)) {
		list_move(&rq->queuelist, &next->queuelist);
		rq->fifo_time = next->fifo_time;
	}

	if (cfqq->next_rq == next)
		cfqq->next_rq = rq;
	cfq_remove_request(next);
	cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags);

	cfqq = RQ_CFQQ(next);
	/*
         * all requests of this queue are merged to other queues, delete it
         * from the service tree. If it's the active_queue,
         * cfq_dispatch_requests() will choose to expire it or do idle
         */
	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) &&
	    cfqq != cfqd->active_queue)
		cfq_del_cfqq_rr(cfqd, cfqq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
48
28.07%
4
30.77%
li shaohua
li shaohua
47
27.49%
1
7.69%
corrado zoccolo
corrado zoccolo
24
14.04%
1
7.69%
andrew morton
andrew morton
24
14.04%
1
7.69%
jan kara
jan kara
9
5.26%
1
7.69%
shaohua li
shaohua li
7
4.09%
1
7.69%
tejun heo
tejun heo
4
2.34%
2
15.38%
vivek goyal
vivek goyal
4
2.34%
1
7.69%
divyesh shah
divyesh shah
4
2.34%
1
7.69%
Total
171
100.00%
13
100.00%



static int cfq_allow_merge(struct request_queue *q, struct request *rq,
			   struct bio *bio)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct cfq_io_cq *cic;
	struct cfq_queue *cfqq;

	/*
         * Disallow merge of a sync bio into an async request.
         */
	if (cfq_bio_sync(bio) && !rq_is_sync(rq))
		return false;

	/*
         * Lookup the cfqq that this bio will be queued with and allow
         * merge only if rq is queued there.
         */
	cic = cfq_cic_lookup(cfqd, current->io_context);
	if (!cic)
		return false;

	cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio));
	return cfqq == RQ_CFQQ(rq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
75
75.76%
6
66.67%
vasily tarasov
vasily tarasov
22
22.22%
1
11.11%
tejun heo
tejun heo
2
2.02%
2
22.22%
Total
99
100.00%
9
100.00%



static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	del_timer(&cfqd->idle_slice_timer);
	cfqg_stats_update_idle_time(cfqq->cfqg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
divyesh shah
divyesh shah
29
90.62%
1
33.33%
tejun heo
tejun heo
3
9.38%
2
66.67%
Total
32
100.00%
3
100.00%



static void __cfq_set_active_queue(struct cfq_data *cfqd,
				   struct cfq_queue *cfqq)
{
	if (cfqq) {
		cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d",
				cfqd->serving_wl_class, cfqd->serving_wl_type);
		cfqg_stats_update_avg_queue_size(cfqq->cfqg);
		cfqq->slice_start = 0;
		cfqq->dispatch_start = jiffies;
		cfqq->allocated_slice = 0;
		cfqq->slice_end = 0;
		cfqq->slice_dispatch = 0;
		cfqq->nr_sectors = 0;

		cfq_clear_cfqq_wait_request(cfqq);
		cfq_clear_cfqq_must_dispatch(cfqq);
		cfq_clear_cfqq_must_alloc_slice(cfqq);
		cfq_clear_cfqq_fifo_expire(cfqq);
		cfq_mark_cfqq_slice_new(cfqq);

		cfq_del_timer(cfqd, cfqq);
	}

	cfqd->active_queue = cfqq;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
53
44.17%
7
38.89%
vivek goyal
vivek goyal
27
22.50%
5
27.78%
justin teravest
justin teravest
20
16.67%
1
5.56%
andrew morton
andrew morton
10
8.33%
1
5.56%
divyesh shah
divyesh shah
7
5.83%
2
11.11%
tejun heo
tejun heo
3
2.50%
2
11.11%
Total
120
100.00%
18
100.00%

/*
 * current cfqq expired its slice (or was too idle), select new one
 */

static void

__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
		    bool timed_out)
{
	cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out);

	if (cfq_cfqq_wait_request(cfqq))
		cfq_del_timer(cfqd, cfqq);

	cfq_clear_cfqq_wait_request(cfqq);
	cfq_clear_cfqq_wait_busy(cfqq);

	/*
         * If this cfqq is shared between multiple processes, check to
         * make sure that those processes are still issuing I/Os within
         * the mean seek distance.  If not, it may be time to break the
         * queues apart again.
         */
	if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq))
		cfq_mark_cfqq_split_coop(cfqq);

	/*
         * store what was left of this slice, if the queue idled/timed out
         */
	if (timed_out) {
		if (cfq_cfqq_slice_new(cfqq))
			cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq);
		else
			cfqq->slice_resid = cfqq->slice_end - jiffies;
		cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid);
	}

	cfq_group_served(cfqd, cfqq->cfqg, cfqq);

	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
		cfq_del_cfqq_rr(cfqd, cfqq);

	cfq_resort_rr_list(cfqd, cfqq);

	if (cfqq == cfqd->active_queue)
		cfqd->active_queue = NULL;

	if (cfqd->active_cic) {
		put_io_context(cfqd->active_cic->icq.ioc);
		cfqd->active_cic = NULL;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
123
61.50%
9
52.94%
vivek goyal
vivek goyal
39
19.50%
4
23.53%
li shaohua
li shaohua
33
16.50%
2
11.76%
divyesh shah
divyesh shah
3
1.50%
1
5.88%
tejun heo
tejun heo
2
1.00%
1
5.88%
Total
200
100.00%
17
100.00%



static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
{
	struct cfq_queue *cfqq = cfqd->active_queue;

	if (cfqq)
		__cfq_slice_expired(cfqd, cfqq, timed_out);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
37
100.00%
4
100.00%
Total
37
100.00%
4
100.00%

/*
 * Get next queue for service. Unless we have a queue preemption,
 * we'll simply select the first cfqq in the service tree.
 */


static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
{
	struct cfq_rb_root *st = st_for(cfqd->serving_group,
			cfqd->serving_wl_class, cfqd->serving_wl_type);

	if (!cfqd->rq_queued)
		return NULL;

	/* There is nothing to dispatch */
	if (!st)
		return NULL;
	if (RB_EMPTY_ROOT(&st->rb))
		return NULL;
	return cfq_rb_first(st);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
29
40.85%
5
41.67%
jens axboe
jens axboe
27
38.03%
4
33.33%
corrado zoccolo
corrado zoccolo
13
18.31%
2
16.67%
andrew morton
andrew morton
2
2.82%
1
8.33%
Total
71
100.00%
12
100.00%



static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
{
	struct cfq_group *cfqg;
	struct cfq_queue *cfqq;
	int i, j;
	struct cfq_rb_root *st;

	if (!cfqd->rq_queued)
		return NULL;

	cfqg = cfq_get_next_cfqg(cfqd);
	if (!cfqg)
		return NULL;

	for_each_cfqg_st(cfqg, i, j, st)
		if ((cfqq = cfq_rb_first(st)) != NULL)
			return cfqq;
	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
87
100.00%
2
100.00%
Total
87
100.00%
2
100.00%

/*
 * Get and set a new active queue for service.
 */


static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd,
					      struct cfq_queue *cfqq)
{
	if (!cfqq)
		cfqq = cfq_get_next_queue(cfqd);

	__cfq_set_active_queue(cfqd, cfqq);
	return cfqq;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
40
100.00%
1
100.00%
Total
40
100.00%
1
100.00%



static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
					  struct request *rq)
{
	if (blk_rq_pos(rq) >= cfqd->last_position)
		return blk_rq_pos(rq) - cfqd->last_position;
	else
		return cfqd->last_position - blk_rq_pos(rq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
40
81.63%
1
50.00%
tejun heo
tejun heo
9
18.37%
1
50.00%
Total
49
100.00%
2
100.00%



static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq,
			       struct request *rq)
{
	return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
26
81.25%
1
33.33%
jeff moyer
jeff moyer
5
15.62%
1
33.33%
li shaohua
li shaohua
1
3.12%
1
33.33%
Total
32
100.00%
3
100.00%



static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
				    struct cfq_queue *cur_cfqq)
{
	struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio];
	struct rb_node *parent, *node;
	struct cfq_queue *__cfqq;
	sector_t sector = cfqd->last_position;

	if (RB_EMPTY_ROOT(root))
		return NULL;

	/*
         * First, if we find a request starting at the end of the last
         * request, choose it.
         */
	__cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL);
	if (__cfqq)
		return __cfqq;

	/*
         * If the exact sector wasn't found, the parent of the NULL leaf
         * will contain the closest sector.
         */
	__cfqq = rb_entry(parent, struct cfq_queue, p_node);
	if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
		return __cfqq;

	if (blk_rq_pos(__cfqq->next_rq) < sector)
		node = rb_next(&__cfqq->p_node);
	else
		node = rb_prev(&__cfqq->p_node);
	if (!node)
		return NULL;

	__cfqq = rb_entry(node, struct cfq_queue, p_node);
	if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
		return __cfqq;

	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
180
96.26%
6
75.00%
jeff moyer
jeff moyer
4
2.14%
1
12.50%
tejun heo
tejun heo
3
1.60%
1
12.50%
Total
187
100.00%
8
100.00%

/*
 * cfqd - obvious
 * cur_cfqq - passed in so that we don't decide that the current queue is
 *            closely cooperating with itself.
 *
 * So, basically we're assuming that that cur_cfqq has dispatched at least
 * one request, and that cfqd->last_position reflects a position on the disk
 * associated with the I/O issued by cur_cfqq.  I'm not sure this is a valid
 * assumption.
 */


static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
					      struct cfq_queue *cur_cfqq)
{
	struct cfq_queue *cfqq;

	if (cfq_class_idle(cur_cfqq))
		return NULL;
	if (!cfq_cfqq_sync(cur_cfqq))
		return NULL;
	if (CFQQ_SEEKY(cur_cfqq))
		return NULL;

	/*
         * Don't search priority tree if it's the only queue in the group.
         */
	if (cur_cfqq->cfqg->nr_cfqq == 1)
		return NULL;

	/*
         * We should notice if some of the queues are cooperating, eg
         * working closely on the same area of the disk. In that case,
         * we can group them together and don't waste time idling.
         */
	cfqq = cfqq_close(cfqd, cur_cfqq);
	if (!cfqq)
		return NULL;

	/* If new queue belongs to different cfq_group, don't choose it */
	if (cur_cfqq->cfqg != cfqq->cfqg)
		return NULL;

	/*
         * It only makes sense to merge sync queues.
         */
	if (!cfq_cfqq_sync(cfqq))
		return NULL;
	if (CFQQ_SEEKY(cfqq))
		return NULL;

	/*
         * Do not merge queues of different priority classes
         */
	if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq))
		return NULL;

	return cfqq;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
44
31.21%
5
45.45%
jeff moyer
jeff moyer
43
30.50%
2
18.18%
corrado zoccolo
corrado zoccolo
16
11.35%
1
9.09%
gui jianfeng
gui jianfeng
14
9.93%
1
9.09%
vivek goyal
vivek goyal
14
9.93%
1
9.09%
divyesh shah
divyesh shah
10
7.09%
1
9.09%
Total
141
100.00%
11
100.00%

/*
 * Determine whether we should enforce idle window for this queue.
 */



static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	enum wl_class_t wl_class = cfqq_class(cfqq);
	struct cfq_rb_root *st = cfqq->service_tree;

	BUG_ON(!st);
	BUG_ON(!st->count);

	if (!cfqd->cfq_slice_idle)
		return false;

	/* We never do for idle class queues. */
	if (wl_class == IDLE_WORKLOAD)
		return false;

	/* We do for queues that were marked with idle window flag. */
	if (cfq_cfqq_idle_window(cfqq) &&
	   !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag))
		return true;

	/*
         * Otherwise, we do only if they are the last ones
         * in their service tree.
         */
	if (st->count == 1 && cfq_cfqq_sync(cfqq) &&
	   !cfq_io_thinktime_big(cfqd, &st->ttime, false))
		return true;
	cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count);
	return false;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
corrado zoccolo
corrado zoccolo
54
38.85%
2
16.67%
vivek goyal
vivek goyal
37
26.62%
5
41.67%
li shaohua
li shaohua
28
20.14%
3
25.00%
divyesh shah
divyesh shah
18
12.95%
1
8.33%
jens axboe
jens axboe
2
1.44%
1
8.33%
Total
139
100.00%
12
100.00%



static void cfq_arm_slice_timer(struct cfq_data *cfqd)
{
	struct cfq_queue *cfqq = cfqd->active_queue;
	struct cfq_rb_root *st = cfqq->service_tree;
	struct cfq_io_cq *cic;
	unsigned long sl, group_idle = 0;

	/*
         * SSD device without seek penalty, disable idling. But only do so
         * for devices that support queuing, otherwise we still have a problem
         * with sync vs async workloads.
         */
	if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)
		return;

	WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
	WARN_ON(cfq_cfqq_slice_new(cfqq));

	/*
         * idle is disabled, either manually or by past process history
         */
	if (!cfq_should_idle(cfqd, cfqq)) {
		/* no queue idling. Check for group idling */
		if (cfqd->cfq_group_idle)
			group_idle = cfqd->cfq_group_idle;
		else
			return;
	}

	/*
         * still active requests from this queue, don't idle
         */
	if (cfqq->dispatched)
		return;

	/*
         * task has exited, don't wait
         */
	cic = cfqd->active_cic;
	if (!cic || !atomic_read(&cic->icq.ioc->active_ref))
		return;

	/*
         * If our average think time is larger than the remaining time
         * slice, then don't idle. This avoids overrunning the allotted
         * time slice.
         */
	if (sample_valid(cic->ttime.ttime_samples) &&
	    (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) {
		cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu",
			     cic->ttime.ttime_mean);
		return;
	}

	/*
         * There are other queues in the group or this is the only group and
         * it has too big thinktime, don't do group idle.
         */
	if (group_idle &&
	    (cfqq->cfqg->nr_cfqq > 1 ||
	     cfq_io_thinktime_big(cfqd, &st->ttime, true)))
		return;

	cfq_mark_cfqq_wait_request(cfqq);

	if (group_idle)
		sl = cfqd->cfq_group_idle;
	else
		sl = cfqd->cfq_slice_idle;

	mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
	cfqg_stats_set_start_idle_time(cfqq->cfqg);
	cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl,
			group_idle ? 1 : 0);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
118
43.87%
12
44.44%
vivek goyal
vivek goyal
51
18.96%
1
3.70%
corrado zoccolo
corrado zoccolo
30
11.15%
3
11.11%
jan kara
jan kara
24
8.92%
1
3.70%
divyesh shah
divyesh shah
18
6.69%
2
7.41%
andrew morton
andrew morton
10
3.72%
1
3.70%
tejun heo
tejun heo
7
2.60%
4
14.81%
li shaohua
li shaohua
6
2.23%
1
3.70%
nikanth karthikesan
nikanth karthikesan
4
1.49%
1
3.70%
joe perches
joe perches
1
0.37%
1
3.70%
Total
269
100.00%
27
100.00%

/*
 * Move request from internal lists to the request queue dispatch list.
 */


static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct cfq_queue *cfqq = RQ_CFQQ(rq);

	cfq_log_cfqq(cfqd, cfqq, "dispatch_insert");

	cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq);
	cfq_remove_request(rq);
	cfqq->dispatched++;
	(RQ_CFQG(rq))->dispatched++;
	elv_dispatch_sort(q, rq);

	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
	cfqq->nr_sectors += blk_rq_sectors(rq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
68
64.15%
10
66.67%
vivek goyal
vivek goyal
19
17.92%
2
13.33%
jeff moyer
jeff moyer
13
12.26%
1
6.67%
corrado zoccolo
corrado zoccolo
5
4.72%
1
6.67%
andrew morton
andrew morton
1
0.94%
1
6.67%
Total
106
100.00%
15
100.00%

/*
 * return expired entry, or NULL to just start from scratch in rbtree
 */


static struct request *cfq_check_fifo(struct cfq_queue *cfqq)
{
	struct request *rq = NULL;

	if (cfq_cfqq_fifo_expire(cfqq))
		return NULL;

	cfq_mark_cfqq_fifo_expire(cfqq);

	if (list_empty(&cfqq->fifo))
		return NULL;

	rq = rq_entry_fifo(cfqq->fifo.next);
	if (time_before(jiffies, rq->fifo_time))
		rq = NULL;

	cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
	return rq;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
83
92.22%
13
86.67%
andrew morton
andrew morton
5
5.56%
1
6.67%
jan kara
jan kara
2
2.22%
1
6.67%
Total
90
100.00%
15
100.00%


static inline int

cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	const int base_rq = cfqd->cfq_slice_async_rq;

	WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR);

	return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
46
97.87%
3
75.00%
namhyung kim
namhyung kim
1
2.13%
1
25.00%
Total
47
100.00%
4
100.00%

/*
 * Must be called with the queue_lock held.
 */


static int cfqq_process_refs(struct cfq_queue *cfqq)
{
	int process_refs, io_refs;

	io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE];
	process_refs = cfqq->ref - io_refs;
	BUG_ON(process_refs < 0);
	return process_refs;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jeff moyer
jeff moyer
50
100.00%
1
100.00%
Total
50
100.00%
1
100.00%



static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
{
	int process_refs, new_process_refs;
	struct cfq_queue *__cfqq;

	/*
         * If there are no process references on the new_cfqq, then it is
         * unsafe to follow the ->new_cfqq chain as other cfqq's in the
         * chain may have dropped their last reference (not just their
         * last process reference).
         */
	if (!cfqq_process_refs(new_cfqq))
		return;

	/* Avoid a circular list and skip interim queue merges */
	while ((__cfqq = new_cfqq->new_cfqq)) {
		if (__cfqq == cfqq)
			return;
		new_cfqq = __cfqq;
	}

	process_refs = cfqq_process_refs(cfqq);
	new_process_refs = cfqq_process_refs(new_cfqq);
	/*
         * If the process for the cfqq has gone away, there is no
         * sense in merging the queues.
         */
	if (process_refs == 0 || new_process_refs == 0)
		return;

	/*
         * Merge in the direction of the lesser amount of work.
         */
	if (new_process_refs >= process_refs) {
		cfqq->new_cfqq = new_cfqq;
		new_cfqq->ref += process_refs;
	} else {
		new_cfqq->new_cfqq = cfqq;
		cfqq->ref += new_process_refs;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jeff moyer
jeff moyer
74
60.66%
3
60.00%
corrado zoccolo
corrado zoccolo
44
36.07%
1
20.00%
li shaohua
li shaohua
4
3.28%
1
20.00%
Total
122
100.00%
5
100.00%



static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd,
			struct cfq_group *cfqg, enum wl_class_t wl_class)
{
	struct cfq_queue *queue;
	int i;
	bool key_valid = false;
	unsigned long lowest_key = 0;
	enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD;

	for (i = 0; i <= SYNC_WORKLOAD; ++i) {
		/* select the one with lowest rb_key */
		queue = cfq_rb_first(st_for(cfqg, wl_class, i));
		if (queue &&
		    (!key_valid || time_before(queue->rb_key, lowest_key))) {
			lowest_key = queue->rb_key;
			cur_best = i;
			key_valid = true;
		}
	}

	return cur_best;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
corrado zoccolo
corrado zoccolo
98
86.73%
1
16.67%
vivek goyal
vivek goyal
15
13.27%
5
83.33%
Total
113
100.00%
6
100.00%


static void

choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
	unsigned slice;
	unsigned count;
	struct cfq_rb_root *st;
	unsigned group_slice;
	enum wl_class_t original_class = cfqd->serving_wl_class;

	/* Choose next priority. RT > BE > IDLE */
	if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
		cfqd->serving_wl_class = RT_WORKLOAD;
	else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg))
		cfqd->serving_wl_class = BE_WORKLOAD;
	else {
		cfqd->serving_wl_class = IDLE_WORKLOAD;
		cfqd->workload_expires = jiffies + 1;
		return;
	}

	if (original_class != cfqd->serving_wl_class)
		goto new_workload;

	/*
         * For RT and BE, we have to choose also the type
         * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload
         * expiration time
         */
	st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
	count = st->count;

	/*
         * check workload expiration, and that we still have other queues ready
         */
	if (count && !time_after(jiffies, cfqd->workload_expires))
		return;

new_workload:
	/* otherwise select new workload type */
	cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg,
					cfqd->serving_wl_class);
	st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
	count = st->count;

	/*
         * the workload slice is computed as a fraction of target latency
         * proportional to the number of queues in that workload, over
         * all the queues in the same priority class
         */
	group_slice = cfq_group_slice(cfqd, cfqg);

	slice = group_slice * count /
		max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class],
		      cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd,
					cfqg));

	if (cfqd->serving_wl_type == ASYNC_WORKLOAD) {
		unsigned int tmp;

		/*
                 * Async queues are currently system wide. Just taking
                 * proportion of queues with-in same group will lead to higher
                 * async ratio system wide as generally root group is going
                 * to have higher weight. A more accurate thing would be to
                 * calculate system wide asnc/sync ratio.
                 */
		tmp = cfqd->cfq_target_latency *
			cfqg_busy_async_queues(cfqd, cfqg);
		tmp = tmp/cfqd->busy_queues;
		slice = min_t(unsigned, slice, tmp);

		/* async workload slice is scaled down according to
                 * the sync/async slice ratio. */
		slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1];
	} else
		/* sync workload slice is at least 2 * cfq_slice_idle */
		slice = max(slice, 2 * cfqd->cfq_slice_idle);

	slice = max_t(unsigned, slice, CFQ_MIN_TT);
	cfq_log(cfqd, "workload slice:%d", slice);
	cfqd->workload_expires = jiffies + slice;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
corrado zoccolo
corrado zoccolo
166
50.30%
1
6.67%
vivek goyal
vivek goyal
110
33.33%
9
60.00%
jeff moyer
jeff moyer
29
8.79%
2
13.33%
li shaohua
li shaohua
14
4.24%
1
6.67%
divyesh shah
divyesh shah
9
2.73%
1
6.67%
tao ma
tao ma
2
0.61%
1
6.67%
Total
330
100.00%
15
100.00%



static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd)
{
	struct cfq_rb_root *st = &cfqd->grp_service_tree;
	struct cfq_group *cfqg;

	if (RB_EMPTY_ROOT(&st->rb))
		return NULL;
	cfqg = cfq_rb_first_group(st);
	update_min_vdisktime(st);
	return cfqg;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
56
100.00%
2
100.00%
Total
56
100.00%
2
100.00%



static void cfq_choose_cfqg(struct cfq_data *cfqd)
{
	struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd);

	cfqd->serving_group = cfqg;

	/* Restore the workload type data */
	if (cfqg->saved_wl_slice) {
		cfqd->workload_expires = jiffies + cfqg->saved_wl_slice;
		cfqd->serving_wl_type = cfqg->saved_wl_type;
		cfqd->serving_wl_class = cfqg->saved_wl_class;
	} else
		cfqd->workload_expires = jiffies - 1;

	choose_wl_class_and_type(cfqd, cfqg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
69
88.46%
5
83.33%
gui jianfeng
gui jianfeng
9
11.54%
1
16.67%
Total
78
100.00%
6
100.00%

/*
 * Select a queue for service. If we have a current active queue,
 * check whether to continue servicing it, or retrieve and set a new one.
 */


static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
{
	struct cfq_queue *cfqq, *new_cfqq = NULL;

	cfqq = cfqd->active_queue;
	if (!cfqq)
		goto new_queue;

	if (!cfqd->rq_queued)
		return NULL;

	/*
         * We were waiting for group to get backlogged. Expire the queue
         */
	if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list))
		goto expire;

	/*
         * The active queue has run out of time, expire it and select new.
         */
	if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) {
		/*
                 * If slice had not expired at the completion of last request
                 * we might not have turned on wait_busy flag. Don't expire
                 * the queue yet. Allow the group to get backlogged.
                 *
                 * The very fact that we have used the slice, that means we
                 * have been idling all along on this queue and it should be
                 * ok to wait for this request to complete.
                 */
		if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list)
		    && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
			cfqq = NULL;
			goto keep_queue;
		} else
			goto check_group_idle;
	}

	/*
         * The active queue has requests and isn't expired, allow it to
         * dispatch.
         */
	if (!RB_EMPTY_ROOT(&cfqq->sort_list))
		goto keep_queue;

	/*
         * If another queue has a request waiting within our mean seek
         * distance, let it run.  The expire code will check for close
         * cooperators and put the close queue at the front of the service
         * tree.  If possible, merge the expiring queue with the new cfqq.
         */
	new_cfqq = cfq_close_cooperator(cfqd, cfqq);
	if (new_cfqq) {
		if (!cfqq->new_cfqq)
			cfq_setup_merge(cfqq, new_cfqq);
		goto expire;
	}

	/*
         * No requests pending. If the active queue still has requests in
         * flight or is idling for a new request, allow either of these
         * conditions to happen (or time out) before selecting a new queue.
         */
	if (timer_pending(&cfqd->idle_slice_timer)) {
		cfqq = NULL;
		goto keep_queue;
	}

	/*
         * This is a deep seek queue, but the device is much faster than
         * the queue can deliver, don't idle
         **/
	if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) &&
	    (cfq_cfqq_slice_new(cfqq) ||
	    (cfqq->slice_end - jiffies > jiffies - cfqq->slice_start))) {
		cfq_clear_cfqq_deep(cfqq);
		cfq_clear_cfqq_idle_window(cfqq);
	}

	if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
		cfqq = NULL;
		goto keep_queue;
	}

	/*
         * If group idle is enabled and there are requests dispatched from
         * this group, wait for requests to complete.
         */
check_group_idle:
	if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 &&
	    cfqq->cfqg->dispatched &&
	    !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) {
		cfqq = NULL;
		goto keep_queue;
	}

expire:
	cfq_slice_expired(cfqd, 0);
new_queue:
	/*
         * Current queue expired. Check if we have to switch to a new
         * service tree
         */
	if (!new_cfqq)
		cfq_choose_cfqg(cfqd);

	cfqq = cfq_set_active_queue(cfqd, new_cfqq);
keep_queue:
	return cfqq;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
134
38.84%
9
40.91%
vivek goyal
vivek goyal
120
34.78%
7
31.82%
li shaohua
li shaohua
61
17.68%
2
9.09%
jeff moyer
jeff moyer
17
4.93%
1
4.55%
corrado zoccolo
corrado zoccolo
13
3.77%
3
13.64%
Total
345
100.00%
22
100.00%



static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
{
	int dispatched = 0;

	while (cfqq->next_rq) {
		cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq);
		dispatched++;
	}

	BUG_ON(!list_empty(&cfqq->fifo));

	/* By default cfqq is not expired if it is empty. Do it explicitly */
	__cfq_slice_expired(cfqq->cfqd, cfqq, 0);
	return dispatched;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
41
61.19%
1
14.29%
jens axboe
jens axboe
14
20.90%
5
71.43%
vivek goyal
vivek goyal
12
17.91%
1
14.29%
Total
67
100.00%
7
100.00%

/*
 * Drain our current requests. Used for barriers and when switching
 * io schedulers on-the-fly.
 */


static int cfq_forced_dispatch(struct cfq_data *cfqd)
{
	struct cfq_queue *cfqq;
	int dispatched = 0;

	/* Expire the timeslice of the current active queue first */
	cfq_slice_expired(cfqd, 0);
	while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) {
		__cfq_set_active_queue(cfqd, cfqq);
		dispatched += __cfq_forced_dispatch_cfqq(cfqq);
	}

	BUG_ON(cfqd->busy_queues);

	cfq_log(cfqd, "forced_dispatch=%d", dispatched);
	return dispatched;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
29
37.66%
1
12.50%
jens axboe
jens axboe
22
28.57%
3
37.50%
divyesh shah
divyesh shah
17
22.08%
1
12.50%
corrado zoccolo
corrado zoccolo
6
7.79%
1
12.50%
vivek goyal
vivek goyal
2
2.60%
1
12.50%
jeff moyer
jeff moyer
1
1.30%
1
12.50%
Total
77
100.00%
8
100.00%



static inline bool cfq_slice_used_soon(struct cfq_data *cfqd,
	struct cfq_queue *cfqq)
{
	/* the queue hasn't finished any request, can't estimate */
	if (cfq_cfqq_slice_new(cfqq))
		return true;
	if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched,
		cfqq->slice_end))
		return true;

	return false;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
li shaohua
li shaohua
53
100.00%
2
100.00%
Total
53
100.00%
2
100.00%



static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	unsigned int max_dispatch;

	/*
         * Drain async requests before we start sync IO
         */
	if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC])
		return false;

	/*
         * If this is an async queue and we have sync IO in flight, let it wait
         */
	if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq))
		return false;

	max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1);
	if (cfq_class_idle(cfqq))
		max_dispatch = 1;

	/*
         * Does this cfqq already have too much IO in flight?
         */
	if (cfqq->dispatched >= max_dispatch) {
		bool promote_sync = false;
		/*
                 * idle queue must always only have a single IO in flight
                 */
		if (cfq_class_idle(cfqq))
			return false;

		/*
                 * If there is only one sync queue
                 * we can ignore async queue here and give the sync
                 * queue no dispatch limit. The reason is a sync queue can
                 * preempt async queue, limiting the sync queue doesn't make
                 * sense. This is useful for aiostress test.
                 */
		if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1)
			promote_sync = true;

		/*
                 * We have other queues, don't allow more IO from this one
                 */
		if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) &&
				!promote_sync)
			return false;

		/*
                 * Sole queue user, no limit
                 */
		if (cfqd->busy_queues == 1 || promote_sync)
			max_dispatch = -1;
		else
			/*
                         * Normally we start throttling cfqq when cfq_quantum/2
                         * requests have been dispatched. But we can drive
                         * deeper queue depths at the beginning of slice
                         * subjected to upper limit of cfq_quantum.
                         * */
			max_dispatch = cfqd->cfq_quantum;
	}

	/*
         * Async queues must wait a bit before being allowed dispatch.
         * We also ramp up the dispatch depth gradually for async IO,
         * based on the last sync IO we serviced
         */
	if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) {
		unsigned long last_sync = jiffies - cfqd->last_delayed_sync;
		unsigned int depth;

		depth = last_sync / cfqd->cfq_slice[1];
		if (!depth && !cfqq->dispatched)
			depth = 1;
		if (depth < max_dispatch)
			max_dispatch = depth;
	}

	/*
         * If we're below the current max, allow a dispatch
         */
	return cfqq->dispatched < max_dispatch;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
172
70.20%
1
12.50%
li shaohua
li shaohua
64
26.12%
4
50.00%
corrado zoccolo
corrado zoccolo
9
3.67%
3
37.50%
Total
245
100.00%
8
100.00%

/*
 * Dispatch a request from cfqq, moving them to the request queue
 * dispatch list.
 */


static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	struct request *rq;

	BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));

	if (!cfq_may_dispatch(cfqd, cfqq))
		return false;

	/*
         * follow expired path, else get first next available
         */
	rq = cfq_check_fifo(cfqq);
	if (!rq)
		rq = cfqq->next_rq;

	/*
         * insert request into driver dispatch list
         */
	cfq_dispatch_insert(cfqd->queue, rq);

	if (!cfqd->active_cic) {
		struct cfq_io_cq *cic = RQ_CIC(rq);

		atomic_long_inc(&cic->icq.ioc->refcount);
		cfqd->active_cic = cic;
	}

	return true;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
110
96.49%
2
50.00%
tejun heo
tejun heo
3
2.63%
1
25.00%
nikanth karthikesan
nikanth karthikesan
1
0.88%
1
25.00%
Total
114
100.00%
4
100.00%

/*
 * Find the cfqq that we need to service and move a request from that to the
 * dispatch list
 */


static int cfq_dispatch_requests(struct request_queue *q, int force)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct cfq_queue *cfqq;

	if (!cfqd->busy_queues)
		return 0;

	if (unlikely(force))
		return cfq_forced_dispatch(cfqd);

	cfqq = cfq_select_queue(cfqd);
	if (!cfqq)
		return 0;

	/*
         * Dispatch a request from this cfqq, if it is allowed
         */
	if (!cfq_dispatch_request(cfqd, cfqq))
		return 0;

	cfqq->slice_dispatch++;
	cfq_clear_cfqq_must_dispatch(cfqq);

	/*
         * expire an async queue immediately if it has used up its slice. idle
         * queue always expire after 1 dispatch round.
         */
	if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) &&
	    cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
	    cfq_class_idle(cfqq))) {
		cfqq->slice_end = jiffies + 1;
		cfq_slice_expired(cfqd, 0);
	}

	cfq_log_cfqq(cfqd, cfqq, "dispatched a request");
	return 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
136
87.18%
13
81.25%
tejun heo
tejun heo
15
9.62%
1
6.25%
shan wei
shan wei
3
1.92%
1
6.25%
vivek goyal
vivek goyal
2
1.28%
1
6.25%
Total
156
100.00%
16
100.00%

/*
 * task holds one reference to the queue, dropped when task exits. each rq
 * in-flight on this queue also holds a reference, dropped when rq is freed.
 *
 * Each cfq queue took a reference on the parent group. Drop it now.
 * queue lock must be held here.
 */


static void cfq_put_queue(struct cfq_queue *cfqq)
{
	struct cfq_data *cfqd = cfqq->cfqd;
	struct cfq_group *cfqg;

	BUG_ON(cfqq->ref <= 0);

	cfqq->ref--;
	if (cfqq->ref)
		return;

	cfq_log_cfqq(cfqd, cfqq, "put_queue");
	BUG_ON(rb_first(&cfqq->sort_list));
	BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]);
	cfqg = cfqq->cfqg;

	if (unlikely(cfqd->active_queue == cfqq)) {
		__cfq_slice_expired(cfqd, cfqq, 0);
		cfq_schedule_dispatch(cfqd);
	}

	BUG_ON(cfq_cfqq_on_rr(cfqq));
	kmem_cache_free(cfq_pool, cfqq);
	cfqg_put(cfqg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
81
59.56%
4
44.44%
vasily tarasov
vasily tarasov
26
19.12%
1
11.11%
vivek goyal
vivek goyal
23
16.91%
2
22.22%
li shaohua
li shaohua
5
3.68%
1
11.11%
tejun heo
tejun heo
1
0.74%
1
11.11%
Total
136
100.00%
9
100.00%



static void cfq_put_cooperator(struct cfq_queue *cfqq)
{
	struct cfq_queue *__cfqq, *next;

	/*
         * If this queue was scheduled to merge with another queue, be
         * sure to drop the reference taken on that queue (and others in
         * the merge chain).  See cfq_setup_merge and cfq_merge_cfqqs.
         */
	__cfqq = cfqq->new_cfqq;
	while (__cfqq) {
		if (__cfqq == cfqq) {
			WARN(1, "cfqq->new_cfqq loop detected\n");
			break;
		}
		next = __cfqq->new_cfqq;
		cfq_put_queue(__cfqq);
		__cfqq = next;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jeff moyer
jeff moyer
52
82.54%
1
20.00%
jens axboe
jens axboe
7
11.11%
2
40.00%
li shaohua
li shaohua
2
3.17%
1
20.00%
al viro
al viro
2
3.17%
1
20.00%
Total
63
100.00%
5
100.00%



static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	if (unlikely(cfqq == cfqd->active_queue)) {
		__cfq_slice_expired(cfqd, cfqq, 0);
		cfq_schedule_dispatch(cfqd);
	}

	cfq_put_cooperator(cfqq);

	cfq_put_queue(cfqq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
li shaohua
li shaohua
47
88.68%
1
33.33%
jens axboe
jens axboe
4
7.55%
1
33.33%
al viro
al viro
2
3.77%
1
33.33%
Total
53
100.00%
3
100.00%



static void cfq_init_icq(struct io_cq *icq)
{
	struct cfq_io_cq *cic = icq_to_cic(icq);

	cic->ttime.last_end_request = jiffies;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
29
100.00%
1
100.00%
Total
29
100.00%
1
100.00%



static void cfq_exit_icq(struct io_cq *icq)
{
	struct cfq_io_cq *cic = icq_to_cic(icq);
	struct cfq_data *cfqd = cic_to_cfqd(cic);

	if (cic_to_cfqq(cic, false)) {
		cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, false));
		cic_set_cfqq(cic, NULL, false);
	}

	if (cic_to_cfqq(cic, true)) {
		cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, true));
		cic_set_cfqq(cic, NULL, true);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
54
56.84%
3
37.50%
jens axboe
jens axboe
25
26.32%
3
37.50%
al viro
al viro
13
13.68%
1
12.50%
fabio checconi
fabio checconi
3
3.16%
1
12.50%
Total
95
100.00%
8
100.00%



static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic)
{
	struct task_struct *tsk = current;
	int ioprio_class;

	if (!cfq_cfqq_prio_changed(cfqq))
		return;

	ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
	switch (ioprio_class) {
	default:
		printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
	case IOPRIO_CLASS_NONE:
		/*
                 * no prio set, inherit CPU scheduling settings
                 */
		cfqq->ioprio = task_nice_ioprio(tsk);
		cfqq->ioprio_class = task_nice_ioclass(tsk);
		break;
	case IOPRIO_CLASS_RT:
		cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
		cfqq->ioprio_class = IOPRIO_CLASS_RT;
		break;
	case IOPRIO_CLASS_BE:
		cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
		cfqq->ioprio_class = IOPRIO_CLASS_BE;
		break;
	case IOPRIO_CLASS_IDLE:
		cfqq->ioprio_class = IOPRIO_CLASS_IDLE;
		cfqq->ioprio = 7;
		cfq_clear_cfqq_idle_window(cfqq);
		break;
	}

	/*
         * keep track of original prio settings in case we have to temporarily
         * elevate the priority of this queue
         */
	cfqq->org_ioprio = cfqq->ioprio;
	cfq_clear_cfqq_prio_changed(cfqq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
147
92.45%
4
66.67%
tejun heo
tejun heo
12
7.55%
2
33.33%
Total
159
100.00%
6
100.00%



static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio)
{
	int ioprio = cic->icq.ioc->ioprio;
	struct cfq_data *cfqd = cic_to_cfqd(cic);
	struct cfq_queue *cfqq;

	/*
         * Check whether ioprio has changed.  The condition may trigger
         * spuriously on a newly created cic but there's no harm.
         */
	if (unlikely(!cfqd) || likely(cic->ioprio == ioprio))
		return;

	cfqq = cic_to_cfqq(cic, false);
	if (cfqq) {
		cfq_put_queue(cfqq);
		cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio);
		cic_set_cfqq(cic, cfqq, false);
	}

	cfqq = cic_to_cfqq(cic, true);
	if (cfqq)
		cfq_mark_cfqq_prio_changed(cfqq);

	cic->ioprio = ioprio;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
56
44.09%
4
33.33%
al viro
al viro
43
33.86%
3
25.00%
jens axboe
jens axboe
25
19.69%
4
33.33%
konstantin khlebnikov
konstantin khlebnikov
3
2.36%
1
8.33%
Total
127
100.00%
12
100.00%



static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
			  pid_t pid, bool is_sync)
{
	RB_CLEAR_NODE(&cfqq->rb_node);
	RB_CLEAR_NODE(&cfqq->p_node);
	INIT_LIST_HEAD(&cfqq->fifo);

	cfqq->ref = 0;
	cfqq->cfqd = cfqd;

	cfq_mark_cfqq_prio_changed(cfqq);

	if (is_sync) {
		if (!cfq_class_idle(cfqq))
			cfq_mark_cfqq_idle_window(cfqq);
		cfq_mark_cfqq_sync(cfqq);
	}
	cfqq->pid = pid;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
92
98.92%
2
66.67%
li shaohua
li shaohua
1
1.08%
1
33.33%
Total
93
100.00%
3
100.00%

#ifdef CONFIG_CFQ_GROUP_IOSCHED


static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
{
	struct cfq_data *cfqd = cic_to_cfqd(cic);
	struct cfq_queue *cfqq;
	uint64_t serial_nr;

	rcu_read_lock();
	serial_nr = bio_blkcg(bio)->css.serial_nr;
	rcu_read_unlock();

	/*
         * Check whether blkcg has changed.  The condition may trigger
         * spuriously on a newly created cic but there's no harm.
         */
	if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr))
		return;

	/*
         * Drop reference to queues.  New queues will be assigned in new
         * group upon arrival of fresh requests.
         */
	cfqq = cic_to_cfqq(cic, false);
	if (cfqq) {
		cfq_log_cfqq(cfqd, cfqq, "changed cgroup");
		cic_set_cfqq(cic, NULL, false);
		cfq_put_queue(cfqq);
	}

	cfqq = cic_to_cfqq(cic, true);
	if (cfqq) {
		cfq_log_cfqq(cfqd, cfqq, "changed cgroup");
		cic_set_cfqq(cic, NULL, true);
		cfq_put_queue(cfqq);
	}

	cic->blkcg_serial_nr = serial_nr;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
95
62.09%
5
71.43%
vivek goyal
vivek goyal
55
35.95%
1
14.29%
konstantin khlebnikov
konstantin khlebnikov
3
1.96%
1
14.29%
Total
153
100.00%
7
100.00%

#else


static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { }
Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
16
100.00%
1
100.00%
Total
16
100.00%
1
100.00%

#endif  /* CONFIG_CFQ_GROUP_IOSCHED */


static struct cfq_queue **

cfq_async_queue_prio(struct cfq_group *cfqg, int ioprio_class, int ioprio)
{
	switch (ioprio_class) {
	case IOPRIO_CLASS_RT:
		return &cfqg->async_cfqq[0][ioprio];
	case IOPRIO_CLASS_NONE:
		ioprio = IOPRIO_NORM;
		/* fall through */
	case IOPRIO_CLASS_BE:
		return &cfqg->async_cfqq[1][ioprio];
	case IOPRIO_CLASS_IDLE:
		return &cfqg->async_idle_cfqq;
	default:
		BUG();
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vasily tarasov
vasily tarasov
60
77.92%
1
25.00%
tejun heo
tejun heo
13
16.88%
2
50.00%
jens axboe
jens axboe
4
5.19%
1
25.00%
Total
77
100.00%
4
100.00%


static struct cfq_queue *

cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
	      struct bio *bio)
{
	int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
	int ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
	struct cfq_queue **async_cfqq = NULL;
	struct cfq_queue *cfqq;
	struct cfq_group *cfqg;

	rcu_read_lock();
	cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio));
	if (!cfqg) {
		cfqq = &cfqd->oom_cfqq;
		goto out;
	}

	if (!is_sync) {
		if (!ioprio_valid(cic->ioprio)) {
			struct task_struct *tsk = current;
			ioprio = task_nice_ioprio(tsk);
			ioprio_class = task_nice_ioclass(tsk);
		}
		async_cfqq = cfq_async_queue_prio(cfqg, ioprio_class, ioprio);
		cfqq = *async_cfqq;
		if (cfqq)
			goto out;
	}

	cfqq = kmem_cache_alloc_node(cfq_pool, GFP_NOWAIT | __GFP_ZERO,
				     cfqd->queue->node);
	if (!cfqq) {
		cfqq = &cfqd->oom_cfqq;
		goto out;
	}

	cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
	cfq_init_prio_data(cfqq, cic);
	cfq_link_cfqq_cfqg(cfqq, cfqg);
	cfq_log_cfqq(cfqd, cfqq, "alloced");

	if (async_cfqq) {
		/* a new async queue is created, pin and remember */
		cfqq->ref++;
		*async_cfqq = cfqq;
	}
out:
	cfqq->ref++;
	rcu_read_unlock();
	return cfqq;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
129
49.81%
9
64.29%
jens axboe
jens axboe
66
25.48%
2
14.29%
jeff moyer
jeff moyer
33
12.74%
1
7.14%
vasily tarasov
vasily tarasov
29
11.20%
1
7.14%
li shaohua
li shaohua
2
0.77%
1
7.14%
Total
259
100.00%
14
100.00%


static void

__cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle)
{
	unsigned long elapsed = jiffies - ttime->last_end_request;
	elapsed = min(elapsed, 2UL * slice_idle);

	ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8;
	ttime->ttime_total = (7*ttime->ttime_total + 256*elapsed) / 8;
	ttime->ttime_mean = (ttime->ttime_total + 128) / ttime->ttime_samples;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
67
77.91%
2
66.67%
li shaohua
li shaohua
19
22.09%
1
33.33%
Total
86
100.00%
3
100.00%


static void

cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
			struct cfq_io_cq *cic)
{
	if (cfq_cfqq_sync(cfqq)) {
		__cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle);
		__cfq_update_io_thinktime(&cfqq->service_tree->ttime,
			cfqd->cfq_slice_idle);
	}
#ifdef CONFIG_CFQ_GROUP_IOSCHED
	__cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle);
#endif
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
li shaohua
li shaohua
72
96.00%
3
60.00%
jens axboe
jens axboe
2
2.67%
1
20.00%
tejun heo
tejun heo
1
1.33%
1
20.00%
Total
75
100.00%
5
100.00%


static void

cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
		       struct request *rq)
{
	sector_t sdist = 0;
	sector_t n_sec = blk_rq_sectors(rq);
	if (cfqq->last_request_pos) {
		if (cfqq->last_request_pos < blk_rq_pos(rq))
			sdist = blk_rq_pos(rq) - cfqq->last_request_pos;
		else
			sdist = cfqq->last_request_pos - blk_rq_pos(rq);
	}

	cfqq->seek_history <<= 1;
	if (blk_queue_nonrot(cfqd->queue))
		cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT);
	else
		cfqq->seek_history |= (sdist > CFQQ_SEEK_THR);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
49
43.75%
4
40.00%
corrado zoccolo
corrado zoccolo
39
34.82%
2
20.00%
jeff moyer
jeff moyer
13
11.61%
2
20.00%
tejun heo
tejun heo
9
8.04%
1
10.00%
li shaohua
li shaohua
2
1.79%
1
10.00%
Total
112
100.00%
10
100.00%

/*
 * Disable idle window if the process thinks too long or seeks so much that
 * it doesn't matter
 */

static void

cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
		       struct cfq_io_cq *cic)
{
	int old_idle, enable_idle;

	/*
         * Don't idle for async or idle io prio class
         */
	if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq))
		return;

	enable_idle = old_idle = cfq_cfqq_idle_window(cfqq);

	if (cfqq->queued[0] + cfqq->queued[1] >= 4)
		cfq_mark_cfqq_deep(cfqq);

	if (cfqq->next_rq && (cfqq->next_rq->cmd_flags & REQ_NOIDLE))
		enable_idle = 0;
	else if (!atomic_read(&cic->icq.ioc->active_ref) ||
		 !cfqd->cfq_slice_idle ||
		 (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq)))
		enable_idle = 0;
	else if (sample_valid(cic->ttime.ttime_samples)) {
		if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle)
			enable_idle = 0;
		else
			enable_idle = 1;
	}

	if (old_idle != enable_idle) {
		cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle);
		if (enable_idle)
			cfq_mark_cfqq_idle_window(cfqq);
		else
			cfq_clear_cfqq_idle_window(cfqq);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
133
66.50%
8
50.00%
corrado zoccolo
corrado zoccolo
53
26.50%
3
18.75%
li shaohua
li shaohua
4
2.00%
1
6.25%
tejun heo
tejun heo
4
2.00%
2
12.50%
nikanth karthikesan
nikanth karthikesan
4
2.00%
1
6.25%
jeff moyer
jeff moyer
2
1.00%
1
6.25%
Total
200
100.00%
16
100.00%

/*
 * Check if new_cfqq should preempt the currently active queue. Return 0 for
 * no or if we aren't sure, a 1 will cause a preempt.
 */

static bool

cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
		   struct request *rq)
{
	struct cfq_queue *cfqq;

	cfqq = cfqd->active_queue;
	if (!cfqq)
		return false;

	if (cfq_class_idle(new_cfqq))
		return false;

	if (cfq_class_idle(cfqq))
		return true;

	/*
         * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice.
         */
	if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq))
		return false;

	/*
         * if the new request is sync, but the currently running queue is
         * not, let the sync request have priority.
         */
	if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq))
		return true;

	/*
         * Treat ancestors of current cgroup the same way as current cgroup.
         * For anybody else we disallow preemption to guarantee service
         * fairness among cgroups.
         */
	if (!cfqg_is_descendant(cfqq->cfqg, new_cfqq->cfqg))
		return false;

	if (cfq_slice_used(cfqq))
		return true;

	/*
         * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice.
         */
	if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq))
		return true;

	WARN_ON_ONCE(cfqq->ioprio_class != new_cfqq->ioprio_class);
	/* Allow preemption only if we are idling on sync-noidle tree */
	if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD &&
	    cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
	    RB_EMPTY_ROOT(&cfqq->sort_list))
		return true;

	/*
         * So both queues are sync. Let the new request get disk time if
         * it's a metadata request and the current queue is doing regular IO.
         */
	if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending)
		return true;

	/* An idle queue should not be idle now for some reason */
	if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq))
		return true;

	if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq))
		return false;

	/*
         * if this request is as-good as one we would expect from the
         * current cfqq, let it preempt
         */
	if (cfq_rq_close(cfqd, cfqq, rq))
		return true;

	return false;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
115
45.63%
6
35.29%
vivek goyal
vivek goyal
40
15.87%
3
17.65%
jan kara
jan kara
36
14.29%
2
11.76%
li shaohua
li shaohua
22
8.73%
1
5.88%
corrado zoccolo
corrado zoccolo
18
7.14%
2
11.76%
divyesh shah
divyesh shah
17
6.75%
1
5.88%
jeff moyer
jeff moyer
2
0.79%
1
5.88%
christoph hellwig
christoph hellwig
2
0.79%
1
5.88%
Total
252
100.00%
17
100.00%

/*
 * cfqq preempts the active queue. if we allowed preempt with no slice left,
 * let it have half of its nominal slice.
 */


static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	enum wl_type_t old_type = cfqq_type(cfqd->active_queue);

	cfq_log_cfqq(cfqd, cfqq, "preempt");
	cfq_slice_expired(cfqd, 1);

	/*
         * workload type is changed, don't save slice, otherwise preempt
         * doesn't happen
         */
	if (old_type != cfqq_type(cfqq))
		cfqq->cfqg->saved_wl_slice = 0;

	/*
         * Put the new queue at the front of the of the current list,
         * so we know that it will be selected next.
         */
	BUG_ON(!cfq_cfqq_on_rr(cfqq));

	cfq_service_tree_add(cfqd, cfqq, 1);

	cfqq->slice_end = 0;
	cfq_mark_cfqq_slice_new(cfqq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
49
53.85%
6
60.00%
li shaohua
li shaohua
34
37.36%
2
20.00%
justin teravest
justin teravest
7
7.69%
1
10.00%
vivek goyal
vivek goyal
1
1.10%
1
10.00%
Total
91
100.00%
10
100.00%

/*
 * Called when a new fs request (rq) is added (to cfqq). Check if there's
 * something we should do about it
 */

static void

cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
		struct request *rq)
{
	struct cfq_io_cq *cic = RQ_CIC(rq);

	cfqd->rq_queued++;
	if (rq->cmd_flags & REQ_PRIO)
		cfqq->prio_pending++;

	cfq_update_io_thinktime(cfqd, cfqq, cic);
	cfq_update_io_seektime(cfqd, cfqq, rq);
	cfq_update_idle_window(cfqd, cfqq, cic);

	cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);

	if (cfqq == cfqd->active_queue) {
		/*
                 * Remember that we saw a request from this process, but
                 * don't start queuing just yet. Otherwise we risk seeing lots
                 * of tiny requests, because we disrupt the normal plugging
                 * and merging. If the request is already larger than a single
                 * page, let it rip immediately. For that case we assume that
                 * merging is already done. Ditto for a busy system that
                 * has other work pending, don't risk delaying until the
                 * idle timer unplug to continue working.
                 */
		if (cfq_cfqq_wait_request(cfqq)) {
			if (blk_rq_bytes(rq) > PAGE_SIZE ||
			    cfqd->busy_queues > 1) {
				cfq_del_timer(cfqd, cfqq);
				cfq_clear_cfqq_wait_request(cfqq);
				__blk_run_queue(cfqd->queue);
			} else {
				cfqg_stats_update_idle_time(cfqq->cfqg);
				cfq_mark_cfqq_must_dispatch(cfqq);
			}
		}
	} else if (cfq_should_preempt(cfqd, cfqq, rq)) {
		/*
                 * not the active queue - expire current slice if it is
                 * idle and has expired it's mean thinktime or this new queue
                 * has some old slice time left and is of higher priority or
                 * this new queue is RT and the current one is BE
                 */
		cfq_preempt_queue(cfqd, cfqq);
		__blk_run_queue(cfqd->queue);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
150
78.95%
13
46.43%
tejun heo
tejun heo
12
6.32%
5
17.86%
divyesh shah
divyesh shah
10
5.26%
3
10.71%
aaron carroll
aaron carroll
5
2.63%
1
3.57%
gui jianfeng
gui jianfeng
5
2.63%
1
3.57%
jeff moyer
jeff moyer
2
1.05%
1
3.57%
li shaohua
li shaohua
2
1.05%
1
3.57%
christoph hellwig
christoph hellwig
2
1.05%
1
3.57%
vivek goyal
vivek goyal
1
0.53%
1
3.57%
kirill a. shutemov
kirill a. shutemov
1
0.53%
1
3.57%
Total
190
100.00%
28
100.00%



static void cfq_insert_request(struct request_queue *q, struct request *rq)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct cfq_queue *cfqq = RQ_CFQQ(rq);

	cfq_log_cfqq(cfqd, cfqq, "insert_request");
	cfq_init_prio_data(cfqq, RQ_CIC(rq));

	rq->fifo_time = jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)];
	list_add_tail(&rq->queuelist, &cfqq->fifo);
	cfq_add_rq_rb(rq);
	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group,
				 rq->cmd_flags);
	cfq_rq_enqueued(cfqd, cfqq, rq);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
91
79.13%
7
50.00%
divyesh shah
divyesh shah
7
6.09%
1
7.14%
corrado zoccolo
corrado zoccolo
5
4.35%
1
7.14%
tejun heo
tejun heo
5
4.35%
3
21.43%
vivek goyal
vivek goyal
4
3.48%
1
7.14%
jan kara
jan kara
3
2.61%
1
7.14%
Total
115
100.00%
14
100.00%

/*
 * Update hw_tag based on peak queue depth over 50 samples under
 * sufficient load.
 */


static void cfq_update_hw_tag(struct cfq_data *cfqd)
{
	struct cfq_queue *cfqq = cfqd->active_queue;

	if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth)
		cfqd->hw_tag_est_depth = cfqd->rq_in_driver;

	if (cfqd->hw_tag == 1)
		return;

	if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN &&
	    cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN)
		return;

	/*
         * If active queue hasn't enough requests and can idle, cfq might not
         * dispatch sufficient requests to hardware. Don't zero hw_tag in this
         * case
         */
	if (cfqq && cfq_cfqq_idle_window(cfqq) &&
	    cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] <
	    CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN)
		return;

	if (cfqd->hw_tag_samples++ < 50)
		return;

	if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN)
		cfqd->hw_tag = 1;
	else
		cfqd->hw_tag = 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
aaron carroll
aaron carroll
63
48.46%
1
20.00%
li shaohua
li shaohua
44
33.85%
1
20.00%
corrado zoccolo
corrado zoccolo
20
15.38%
2
40.00%
jens axboe
jens axboe
3
2.31%
1
20.00%
Total
130
100.00%
5
100.00%



static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
	struct cfq_io_cq *cic = cfqd->active_cic;

	/* If the queue already has requests, don't wait */
	if (!RB_EMPTY_ROOT(&cfqq->sort_list))
		return false;

	/* If there are other queues in the group, don't wait */
	if (cfqq->cfqg->nr_cfqq > 1)
		return false;

	/* the only queue in the group, but think time is big */
	if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true))
		return false;

	if (cfq_slice_used(cfqq))
		return true;

	/* if slice left is less than think time, wait busy */
	if (cic && sample_valid(cic->ttime.ttime_samples)
	    && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean))
		return true;

	/*
         * If think times is less than a jiffy than ttime_mean=0 and above
         * will not be true. It might happen that slice has not expired yet
         * but will expire soon (4-5 ns) during select_queue(). To cover the
         * case where think time is less than a jiffy, mark the queue wait
         * busy if only 1 jiffy is left in the slice.
         */
	if (cfqq->slice_end - jiffies == 1)
		return true;

	return false;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
vivek goyal
vivek goyal
92
69.70%
1
20.00%
li shaohua
li shaohua
24
18.18%
2
40.00%
justin teravest
justin teravest
15
11.36%
1
20.00%
tejun heo
tejun heo
1
0.76%
1
20.00%
Total
132
100.00%
5
100.00%



static void cfq_completed_request(struct request_queue *q, struct request *rq)
{
	struct cfq_queue *cfqq = RQ_CFQQ(rq);
	struct cfq_data *cfqd = cfqq->cfqd;
	const int sync = rq_is_sync(rq);
	unsigned long now;

	now = jiffies;
	cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d",
		     !!(rq->cmd_flags & REQ_NOIDLE));

	cfq_update_hw_tag(cfqd);

	WARN_ON(!cfqd->rq_in_driver);
	WARN_ON(!cfqq->dispatched);
	cfqd->rq_in_driver--;
	cfqq->dispatched--;
	(RQ_CFQG(rq))->dispatched--;
	cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq),
				     rq_io_start_time_ns(rq), rq->cmd_flags);

	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;

	if (sync) {
		struct cfq_rb_root *st;

		RQ_CIC(rq)->ttime.last_end_request = now;

		if (cfq_cfqq_on_rr(cfqq))
			st = cfqq->service_tree;
		else
			st = st_for(cfqq->cfqg, cfqq_class(cfqq),
					cfqq_type(cfqq));

		st->ttime.last_end_request = now;
		if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now))
			cfqd->last_delayed_sync = now;
	}

#ifdef CONFIG_CFQ_GROUP_IOSCHED
	cfqq->cfqg->ttime.last_end_request = now;
#endif

	/*
         * If this is the active queue, check if it needs to be expired,
         * or if we want to idle in case it has no pending requests.
         */
	if (cfqd->active_queue == cfqq) {
		const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list);

		if (cfq_cfqq_slice_new(cfqq)) {
			cfq_set_prio_slice(cfqd, cfqq);
			cfq_clear_cfqq_slice_new(cfqq);
		}

		/*
                 * Should we wait for next request to come in before we expire
                 * the queue.
                 */
		if (cfq_should_wait_busy(cfqd, cfqq)) {
			unsigned long extend_sl = cfqd->cfq_slice_idle;
			if (!cfqd->cfq_slice_idle)
				extend_sl = cfqd->cfq_group_idle;
			cfqq->slice_end = jiffies + extend_sl;
			cfq_mark_cfqq_wait_busy(cfqq);
			cfq_log_cfqq(cfqd, cfqq, "will busy wait");
		}

		/*
                 * Idling is not enabled on:
                 * - expired queues
                 * - idle-priority queues
                 * - async queues
                 * - queues with still some requests queued
                 * - when there is a close cooperator
                 */
		if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
			cfq_slice_expired(cfqd, 1);
		else if (sync && cfqq_empty &&
			 !cfq_close_cooperator(cfqd, cfqq)) {
			cfq_arm_slice_timer(cfqd);
		}
	}

	if (!cfqd->rq_in_driver)
		cfq_schedule_dispatch(cfqd);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
195
48.75%
17
44.74%
vivek goyal
vivek goyal
74
18.50%
7
18.42%
li shaohua
li shaohua
57
14.25%
3
7.89%
corrado zoccolo
corrado zoccolo
33
8.25%
3
7.89%
divyesh shah
divyesh shah
25
6.25%
3
7.89%
christoph hellwig
christoph hellwig
6
1.50%
1
2.63%
tejun heo
tejun heo
5
1.25%
3
7.89%
aaron carroll
aaron carroll
5
1.25%
1
2.63%
Total
400
100.00%
38
100.00%



static inline int __cfq_may_queue(struct cfq_queue *cfqq)
{
	if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) {
		cfq_mark_cfqq_must_alloc_slice(cfqq);
		return ELV_MQUEUE_MUST;
	}

	return ELV_MQUEUE_MAY;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
35
92.11%
3
75.00%
andrew morton
andrew morton
3
7.89%
1
25.00%
Total
38
100.00%
4
100.00%



static int cfq_may_queue(struct request_queue *q, int rw)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct task_struct *tsk = current;
	struct cfq_io_cq *cic;
	struct cfq_queue *cfqq;

	/*
         * don't force setup of a queue from here, as a call to may_queue
         * does not necessarily imply that a request actually will be queued.
         * so just lookup a possibly existing queue, or return 'may queue'
         * if that fails
         */
	cic = cfq_cic_lookup(cfqd, tsk->io_context);
	if (!cic)
		return ELV_MQUEUE_MAY;

	cfqq = cic_to_cfqq(cic, rw_is_sync(rw));
	if (cfqq) {
		cfq_init_prio_data(cfqq, cic);

		return __cfq_may_queue(cfqq);
	}

	return ELV_MQUEUE_MAY;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
74
77.08%
8
80.00%
vasily tarasov
vasily tarasov
21
21.88%
1
10.00%
tejun heo
tejun heo
1
1.04%
1
10.00%
Total
96
100.00%
10
100.00%

/*
 * queue lock held here
 */


static void cfq_put_request(struct request *rq)
{
	struct cfq_queue *cfqq = RQ_CFQQ(rq);

	if (cfqq) {
		const int rw = rq_data_dir(rq);

		BUG_ON(!cfqq->allocated[rw]);
		cfqq->allocated[rw]--;

		/* Put down rq reference on cfqg */
		cfqg_put(RQ_CFQG(rq));
		rq->elv.priv[0] = NULL;
		rq->elv.priv[1] = NULL;

		cfq_put_queue(cfqq);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
60
65.93%
3
42.86%
tejun heo
tejun heo
16
17.58%
2
28.57%
vivek goyal
vivek goyal
13
14.29%
1
14.29%
mike snitzer
mike snitzer
2
2.20%
1
14.29%
Total
91
100.00%
7
100.00%


static struct cfq_queue *

cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic,
		struct cfq_queue *cfqq)
{
	cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq);
	cic_set_cfqq(cic, cfqq->new_cfqq, 1);
	cfq_mark_cfqq_coop(cfqq->new_cfqq);
	cfq_put_queue(cfqq);
	return cic_to_cfqq(cic, 1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jeff moyer
jeff moyer
66
98.51%
2
66.67%
tejun heo
tejun heo
1
1.49%
1
33.33%
Total
67
100.00%
3
100.00%

/*
 * Returns NULL if a new cfqq should be allocated, or the old cfqq if this
 * was the last process referring to said cfqq.
 */

static struct cfq_queue *

split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq)
{
	if (cfqq_process_refs(cfqq) == 1) {
		cfqq->pid = current->pid;
		cfq_clear_cfqq_coop(cfqq);
		cfq_clear_cfqq_split_coop(cfqq);
		return cfqq;
	}

	cic_set_cfqq(cic, NULL, 1);

	cfq_put_cooperator(cfqq);

	cfq_put_queue(cfqq);
	return NULL;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
jeff moyer
jeff moyer
61
84.72%
1
25.00%
li shaohua
li shaohua
10
13.89%
2
50.00%
tejun heo
tejun heo
1
1.39%
1
25.00%
Total
72
100.00%
4
100.00%

/*
 * Allocate cfq data structures associated with this request.
 */

static int

cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
		gfp_t gfp_mask)
{
	struct cfq_data *cfqd = q->elevator->elevator_data;
	struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq);
	const int rw = rq_data_dir(rq);
	const bool is_sync = rq_is_sync(rq);
	struct cfq_queue *cfqq;

	spin_lock_irq(q->queue_lock);

	check_ioprio_changed(cic, bio);
	check_blkcg_changed(cic, bio);
new_queue:
	cfqq = cic_to_cfqq(cic, is_sync);
	if (!cfqq || cfqq == &cfqd->oom_cfqq) {
		if (cfqq)
			cfq_put_queue(cfqq);
		cfqq = cfq_get_queue(cfqd, is_sync, cic, bio);
		cic_set_cfqq(cic, cfqq, is_sync);
	} else {
		/*
                 * If the queue was seeky for too long, break it apart.
                 */
		if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) {
			cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq");
			cfqq = split_cfqq(cic, cfqq);
			if (!cfqq)
				goto new_queue;
		}

		/*
                 * Check to see if this queue is scheduled to merge with
                 * another, closely cooperating queue.  The merging of
                 * queues happens here as it must be done in process context.
                 * The reference on new_cfqq was taken in merge_cfqqs.
                 */
		if (cfqq->new_cfqq)
			cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq);
	}

	cfqq->allocated[rw]++;

	cfqq->ref++;
	cfqg_get(cfqq->cfqg);
	rq->elv.priv[0] = cfqq;
	rq->elv.priv[1] = cfqq->cfqg;
	spin_unlock_irq(q->queue_lock);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
105
39.62%
9
31.03%
jeff moyer
jeff moyer
63
23.77%
2
6.90%
tejun heo
tejun heo
60
22.64%
10
34.48%
vasily tarasov
vasily tarasov
15
5.66%
1
3.45%
vivek goyal
vivek goyal
14
5.28%
2
6.90%
mike snitzer
mike snitzer
4
1.51%
1
3.45%
al viro
al viro
2
0.75%
2
6.90%
li shaohua
li shaohua
2
0.75%
2
6.90%
Total
265
100.00%
29
100.00%



static void cfq_kick_queue(struct work_struct *work)
{
	struct cfq_data *cfqd =
		container_of(work, struct cfq_data, unplug_work);
	struct request_queue *q = cfqd->queue;

	spin_lock_irq(q->queue_lock);
	__blk_run_queue(cfqd->queue);
	spin_unlock_irq(q->queue_lock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
31
55.36%
4
66.67%
david howells
david howells
21
37.50%
1
16.67%
tejun heo
tejun heo
4
7.14%
1
16.67%
Total
56
100.00%
6
100.00%

/*
 * Timer running if the active_queue is currently idling inside its time slice
 */


static void cfq_idle_slice_timer(unsigned long data)
{
	struct cfq_data *cfqd = (struct cfq_data *) data;
	struct cfq_queue *cfqq;
	unsigned long flags;
	int timed_out = 1;

	cfq_log(cfqd, "idle timer fired");

	spin_lock_irqsave(cfqd->queue->queue_lock, flags);

	cfqq = cfqd->active_queue;
	if (cfqq) {
		timed_out = 0;

		/*
                 * We saw a request before the queue expired, let it through
                 */
		if (cfq_cfqq_must_dispatch(cfqq))
			goto out_kick;

		/*
                 * expired
                 */
		if (cfq_slice_used(cfqq))
			goto expire;

		/*
                 * only expire and reinvoke request handler, if there are
                 * other queues with pending requests
                 */
		if (!cfqd->busy_queues)
			goto out_cont;

		/*
                 * not expired and it has a request pending, let it dispatch
                 */
		if (!RB_EMPTY_ROOT(&cfqq->sort_list))
			goto out_kick;

		/*
                 * Queue depth flag is reset only when the idle didn't succeed
                 */
		cfq_clear_cfqq_deep(cfqq);
	}
expire:
	cfq_slice_expired(cfqd, timed_out);
out_kick:
	cfq_schedule_dispatch(cfqd);
out_cont:
	spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
147
96.08%
11
91.67%
corrado zoccolo
corrado zoccolo
6
3.92%
1
8.33%
Total
153
100.00%
12
100.00%



static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
{
	del_timer_sync(&cfqd->idle_slice_timer);
	cancel_work_sync(&cfqd->unplug_work);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
25
92.59%
2
66.67%
oleg nesterov
oleg nesterov
2
7.41%
1
33.33%
Total
27
100.00%
3
100.00%



static void cfq_exit_queue(struct elevator_queue *e)
{
	struct cfq_data *cfqd = e->elevator_data;
	struct request_queue *q = cfqd->queue;

	cfq_shutdown_timer_wq(cfqd);

	spin_lock_irq(q->queue_lock);

	if (cfqd->active_queue)
		__cfq_slice_expired(cfqd, cfqd->active_queue, 0);

	spin_unlock_irq(q->queue_lock);

	cfq_shutdown_timer_wq(cfqd);

#ifdef CONFIG_CFQ_GROUP_IOSCHED
	blkcg_deactivate_policy(q, &blkcg_policy_cfq);
#else
	kfree(cfqd->root_group);
#endif
	kfree(cfqd);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
38
39.18%
2
15.38%
jens axboe
jens axboe
29
29.90%
5
38.46%
tejun heo
tejun heo
19
19.59%
3
23.08%
vivek goyal
vivek goyal
11
11.34%
3
23.08%
Total
97
100.00%
13
100.00%



static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
{
	struct cfq_data *cfqd;
	struct blkcg_gq *blkg __maybe_unused;
	int i, ret;
	struct elevator_queue *eq;

	eq = elevator_alloc(q, e);
	if (!eq)
		return -ENOMEM;

	cfqd = kzalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node);
	if (!cfqd) {
		kobject_put(&eq->kobj);
		return -ENOMEM;
	}
	eq->elevator_data = cfqd;

	cfqd->queue = q;
	spin_lock_irq(q->queue_lock);
	q->elevator = eq;
	spin_unlock_irq(q->queue_lock);

	/* Init root service tree */
	cfqd->grp_service_tree = CFQ_RB_ROOT;

	/* Init root group and prefer root group over other groups by default */
#ifdef CONFIG_CFQ_GROUP_IOSCHED
	ret = blkcg_activate_policy(q, &blkcg_policy_cfq);
	if (ret)
		goto out_free;

	cfqd->root_group = blkg_to_cfqg(q->root_blkg);
#else
	ret = -ENOMEM;
	cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group),
					GFP_KERNEL, cfqd->queue->node);
	if (!cfqd->root_group)
		goto out_free;

	cfq_init_cfqg_base(cfqd->root_group);
	cfqd->root_group->weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
	cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
#endif

	/*
         * Not strictly needed (since RB_ROOT just clears the node and we
         * zeroed cfqd on alloc), but better be safe in case someone decides
         * to add magic to the rb code
         */
	for (i = 0; i < CFQ_PRIO_LISTS; i++)
		cfqd->prio_trees[i] = RB_ROOT;

	/*
         * Our fallback cfqq if cfq_get_queue() runs into OOM issues.
         * Grab a permanent reference to it, so that the normal code flow
         * will not attempt to free it.  oom_cfqq is linked to root_group
         * but shouldn't hold a reference as it'll never be unlinked.  Lose
         * the reference from linking right away.
         */
	cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0);
	cfqd->oom_cfqq.ref++;

	spin_lock_irq(q->queue_lock);
	cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group);
	cfqg_put(cfqd->root_group);
	spin_unlock_irq(q->queue_lock);

	init_timer(&cfqd->idle_slice_timer);
	cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
	cfqd->idle_slice_timer.data = (unsigned long) cfqd;

	INIT_WORK(&cfqd->unplug_work, cfq_kick_queue);

	cfqd->cfq_quantum = cfq_quantum;
	cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];
	cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1];
	cfqd->cfq_back_max = cfq_back_max;
	cfqd->cfq_back_penalty = cfq_back_penalty;
	cfqd->cfq_slice[0] = cfq_slice_async;
	cfqd->cfq_slice[1] = cfq_slice_sync;
	cfqd->cfq_target_latency = cfq_target_latency;
	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
	cfqd->cfq_slice_idle = cfq_slice_idle;
	cfqd->cfq_group_idle = cfq_group_idle;
	cfqd->cfq_latency = 1;
	cfqd->hw_tag = -1;
	/*
         * we optimistically start assuming sync ops weren't delayed in last
         * second, in order to have larger depth for async operations.
         */
	cfqd->last_delayed_sync = jiffies - HZ;
	return 0;

out_free:
	kfree(cfqd);
	kobject_put(&eq->kobj);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
203
42.83%
9
23.68%
tejun heo
tejun heo
131
27.64%
12
31.58%
ma jianpeng
ma jianpeng
67
14.14%
1
2.63%
vivek goyal
vivek goyal
54
11.39%
9
23.68%
tao ma
tao ma
6
1.27%
1
2.63%
aaron carroll
aaron carroll
6
1.27%
1
2.63%
corrado zoccolo
corrado zoccolo
5
1.05%
3
7.89%
li shaohua
li shaohua
1
0.21%
1
2.63%
joe perches
joe perches
1
0.21%
1
2.63%
Total
474
100.00%
38
100.00%



static void cfq_registered_queue(struct request_queue *q)
{
	struct elevator_queue *e = q->elevator;
	struct cfq_data *cfqd = e->elevator_data;

	/*
         * Default to IOPS mode with no idling for SSDs
         */
	if (blk_queue_nonrot(q))
		cfqd->cfq_slice_idle = 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
43
100.00%
1
100.00%
Total
43
100.00%
1
100.00%

/*
 * sysfs parts below -->
 */

static ssize_t

cfq_var_show(unsigned int var, char *page)
{
	return sprintf(page, "%u\n", var);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
23
95.83%
1
50.00%
masanari iida
masanari iida
1
4.17%
1
50.00%
Total
24
100.00%
2
100.00%


static ssize_t

cfq_var_store(unsigned int *var, const char *page, size_t count)
{
	char *p = (char *) page;

	*var = simple_strtoul(p, &p, 10);
	return count;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
45
100.00%
1
100.00%
Total
45
100.00%
1
100.00%


#define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
static ssize_t __FUNC(struct elevator_queue *e, char *page)             \
{                                                                       \
        struct cfq_data *cfqd = e->elevator_data;                       \
        unsigned int __data = __VAR;                                    \
        if (__CONV)                                                     \
                __data = jiffies_to_msecs(__data);                      \
        return cfq_var_show(__data, (page));                            \
}
SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0);
SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1);
SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1);
SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0);
SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0);
SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1);
SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1);
SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0);
SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1);

#undef SHOW_FUNCTION


#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
{                                                                       \
        struct cfq_data *cfqd = e->elevator_data;                       \
        unsigned int __data;                                            \
        int ret = cfq_var_store(&__data, (page), count);                \
        if (__data < (MIN))                                             \
                __data = (MIN);                                         \
        else if (__data > (MAX))                                        \
                __data = (MAX);                                         \
        if (__CONV)                                                     \
                *(__PTR) = msecs_to_jiffies(__data);                    \
        else                                                            \
                *(__PTR) = __data;                                      \
        return ret;                                                     \
}
STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0);
STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1,
		UINT_MAX, 1);
STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1,
		UINT_MAX, 1);
STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0);
STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1,
		UINT_MAX, 0);
STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1);
STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
		UINT_MAX, 0);
STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0);
STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1);

#undef STORE_FUNCTION


#define CFQ_ATTR(name) \
	__ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store)


static struct elv_fs_entry cfq_attrs[] = {
	CFQ_ATTR(quantum),
	CFQ_ATTR(fifo_expire_sync),
	CFQ_ATTR(fifo_expire_async),
	CFQ_ATTR(back_seek_max),
	CFQ_ATTR(back_seek_penalty),
	CFQ_ATTR(slice_sync),
	CFQ_ATTR(slice_async),
	CFQ_ATTR(slice_async_rq),
	CFQ_ATTR(slice_idle),
	CFQ_ATTR(group_idle),
	CFQ_ATTR(low_latency),
	CFQ_ATTR(target_latency),
	__ATTR_NULL
};


static struct elevator_type iosched_cfq = {
	.ops = {
		.elevator_merge_fn = 		cfq_merge,
		.elevator_merged_fn =		cfq_merged_request,
		.elevator_merge_req_fn =	cfq_merged_requests,
		.elevator_allow_merge_fn =	cfq_allow_merge,
		.elevator_bio_merged_fn =	cfq_bio_merged,
		.elevator_dispatch_fn =		cfq_dispatch_requests,
		.elevator_add_req_fn =		cfq_insert_request,
		.elevator_activate_req_fn =	cfq_activate_request,
		.elevator_deactivate_req_fn =	cfq_deactivate_request,
		.elevator_completed_req_fn =	cfq_completed_request,
		.elevator_former_req_fn =	elv_rb_former_request,
		.elevator_latter_req_fn =	elv_rb_latter_request,
		.elevator_init_icq_fn =		cfq_init_icq,
		.elevator_exit_icq_fn =		cfq_exit_icq,
		.elevator_set_req_fn =		cfq_set_request,
		.elevator_put_req_fn =		cfq_put_request,
		.elevator_may_queue_fn =	cfq_may_queue,
		.elevator_init_fn =		cfq_init_queue,
		.elevator_exit_fn =		cfq_exit_queue,
		.elevator_registered_fn =	cfq_registered_queue,
        },
	.icq_size	=	sizeof(struct cfq_io_cq),
	.icq_align	=	__alignof__(struct cfq_io_cq),
	.elevator_attrs =	cfq_attrs,
	.elevator_name	=	"cfq",
	.elevator_owner =	THIS_MODULE,
};

#ifdef CONFIG_CFQ_GROUP_IOSCHED

static struct blkcg_policy blkcg_policy_cfq = {
	.dfl_cftypes		= cfq_blkcg_files,
	.legacy_cftypes		= cfq_blkcg_legacy_files,

	.cpd_alloc_fn		= cfq_cpd_alloc,
	.cpd_init_fn		= cfq_cpd_init,
	.cpd_free_fn		= cfq_cpd_free,
	.cpd_bind_fn		= cfq_cpd_bind,

	.pd_alloc_fn		= cfq_pd_alloc,
	.pd_init_fn		= cfq_pd_init,
	.pd_offline_fn		= cfq_pd_offline,
	.pd_free_fn		= cfq_pd_free,
	.pd_reset_stats_fn	= cfq_pd_reset_stats,
};
#endif



static int __init cfq_init(void)
{
	int ret;

	/*
         * could be 0 on HZ < 1000 setups
         */
	if (!cfq_slice_async)
		cfq_slice_async = 1;
	if (!cfq_slice_idle)
		cfq_slice_idle = 1;

#ifdef CONFIG_CFQ_GROUP_IOSCHED
	if (!cfq_group_idle)
		cfq_group_idle = 1;

	ret = blkcg_policy_register(&blkcg_policy_cfq);
	if (ret)
		return ret;
#else
	cfq_group_idle = 0;
#endif

	ret = -ENOMEM;
	cfq_pool = KMEM_CACHE(cfq_queue, 0);
	if (!cfq_pool)
		goto err_pol_unreg;

	ret = elv_register(&iosched_cfq);
	if (ret)
		goto err_free_pool;

	return 0;

err_free_pool:
	kmem_cache_destroy(cfq_pool);
err_pol_unreg:
#ifdef CONFIG_CFQ_GROUP_IOSCHED
	blkcg_policy_unregister(&blkcg_policy_cfq);
#endif
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
74
57.36%
5
50.00%
jens axboe
jens axboe
37
28.68%
2
20.00%
vivek goyal
vivek goyal
16
12.40%
2
20.00%
andries brouwer
andries brouwer
2
1.55%
1
10.00%
Total
129
100.00%
10
100.00%



static void __exit cfq_exit(void)
{
#ifdef CONFIG_CFQ_GROUP_IOSCHED
	blkcg_policy_unregister(&blkcg_policy_cfq);
#endif
	elv_unregister(&iosched_cfq);
	kmem_cache_destroy(cfq_pool);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
14
45.16%
3
37.50%
tejun heo
tejun heo
11
35.48%
3
37.50%
vivek goyal
vivek goyal
4
12.90%
1
12.50%
christoph hellwig
christoph hellwig
2
6.45%
1
12.50%
Total
31
100.00%
8
100.00%


module_init(cfq_init);

module_exit(cfq_exit);

MODULE_AUTHOR("Jens Axboe");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
jens axboe
jens axboe
6626
33.26%
105
29.41%
tejun heo
tejun heo
6012
30.18%
89
24.93%
vivek goyal
vivek goyal
2581
12.96%
42
11.76%
corrado zoccolo
corrado zoccolo
1173
5.89%
18
5.04%
li shaohua
li shaohua
816
4.10%
21
5.88%
jeff moyer
jeff moyer
542
2.72%
9
2.52%
andrew morton
andrew morton
387
1.94%
2
0.56%
vasily tarasov
vasily tarasov
278
1.40%
2
0.56%
divyesh shah
divyesh shah
233
1.17%
11
3.08%
justin teravest
justin teravest
219
1.10%
4
1.12%
arianna avanzini
arianna avanzini
180
0.90%
1
0.28%
al viro
al viro
167
0.84%
9
2.52%
jan kara
jan kara
137
0.69%
4
1.12%
peter zijlstra
peter zijlstra
100
0.50%
1
0.28%
aaron carroll
aaron carroll
99
0.50%
1
0.28%
ma jianpeng
ma jianpeng
67
0.34%
1
0.28%
andreas mohr
andreas mohr
55
0.28%
1
0.28%
tao ma
tao ma
44
0.22%
1
0.28%
gui jianfeng
gui jianfeng
37
0.19%
5
1.40%
toshiaki makita
toshiaki makita
31
0.16%
2
0.56%
christoph hellwig
christoph hellwig
25
0.13%
4
1.12%
konstantin khlebnikov
konstantin khlebnikov
22
0.11%
1
0.28%
david howells
david howells
21
0.11%
1
0.28%
nikanth karthikesan
nikanth karthikesan
9
0.05%
2
0.56%
shaohua li
shaohua li
7
0.04%
1
0.28%
richard kennedy
richard kennedy
7
0.04%
1
0.28%
arjan van de ven
arjan van de ven
6
0.03%
1
0.28%
mike snitzer
mike snitzer
6
0.03%
1
0.28%
namhyung kim
namhyung kim
5
0.03%
2
0.56%
kent overstreet
kent overstreet
4
0.02%
1
0.28%
joe perches
joe perches
3
0.02%
2
0.56%
fabio checconi
fabio checconi
3
0.02%
1
0.28%
shan wei
shan wei
3
0.02%
1
0.28%
randy dunlap
randy dunlap
3
0.02%
1
0.28%
anatol pomozov
anatol pomozov
3
0.02%
1
0.28%
oleg nesterov
oleg nesterov
2
0.01%
1
0.28%
christoph lameter
christoph lameter
2
0.01%
1
0.28%
andries brouwer
andries brouwer
2
0.01%
1
0.28%
kyungmin park
kyungmin park
1
0.01%
1
0.28%
kirill a. shutemov
kirill a. shutemov
1
0.01%
1
0.28%
lucas de marchi
lucas de marchi
1
0.01%
1
0.28%
masanari iida
masanari iida
1
0.01%
1
0.28%
Total
19921
100.00%
357
100.00%
  
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