| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jens Axboe | 6433 | 31.74% | 108 | 27.76% |
| Tejun Heo | 5908 | 29.15% | 91 | 23.39% |
| Vivek Goyal | 2419 | 11.93% | 42 | 10.80% |
| Corrado Zoccolo | 1113 | 5.49% | 18 | 4.63% |
| Jeff Moyer | 1002 | 4.94% | 11 | 2.83% |
| Shaohua Li | 811 | 4.00% | 23 | 5.91% |
| Andrew Morton | 396 | 1.95% | 2 | 0.51% |
| Vasily Tarasov | 250 | 1.23% | 2 | 0.51% |
| Divyesh Shah | 225 | 1.11% | 11 | 2.83% |
| Justin TerAvest | 212 | 1.05% | 4 | 1.03% |
| Jan Kara | 182 | 0.90% | 8 | 2.06% |
| Arianna Avanzini | 180 | 0.89% | 1 | 0.26% |
| Al Viro | 166 | 0.82% | 9 | 2.31% |
| Davidlohr Bueso A | 104 | 0.51% | 2 | 0.51% |
| Peter Zijlstra | 100 | 0.49% | 1 | 0.26% |
| Aaron Carroll | 99 | 0.49% | 1 | 0.26% |
| Christoph Hellwig | 86 | 0.42% | 6 | 1.54% |
| Jianpeng Ma | 67 | 0.33% | 1 | 0.26% |
| Andreas Mohr | 55 | 0.27% | 1 | 0.26% |
| Glauber de Oliveira Costa | 46 | 0.23% | 1 | 0.26% |
| Tao Ma | 42 | 0.21% | 1 | 0.26% |
| Hou Tao | 42 | 0.21% | 1 | 0.26% |
| Tahsin Erdogan | 41 | 0.20% | 1 | 0.26% |
| Omar Sandoval | 40 | 0.20% | 2 | 0.51% |
| Gui Jianfeng | 36 | 0.18% | 5 | 1.29% |
| Maciej S. Szmigiero | 36 | 0.18% | 1 | 0.26% |
| Toshiaki Makita | 31 | 0.15% | 2 | 0.51% |
| Konstantin Khlebnikov | 22 | 0.11% | 1 | 0.26% |
| David Howells | 21 | 0.10% | 1 | 0.26% |
| Michael Christie | 20 | 0.10% | 2 | 0.51% |
| Nikanth Karthikesan | 9 | 0.04% | 2 | 0.51% |
| Alexander Potapenko | 7 | 0.03% | 1 | 0.26% |
| SF Markus Elfring | 6 | 0.03% | 1 | 0.26% |
| Mike Snitzer | 6 | 0.03% | 1 | 0.26% |
| Arjan van de Ven | 6 | 0.03% | 1 | 0.26% |
| Namhyung Kim | 5 | 0.02% | 2 | 0.51% |
| Richard Kennedy | 5 | 0.02% | 1 | 0.26% |
| Ritesh Harjani | 5 | 0.02% | 1 | 0.26% |
| Kent Overstreet | 4 | 0.02% | 1 | 0.26% |
| Bart Van Assche | 3 | 0.01% | 2 | 0.51% |
| Ingo Molnar | 3 | 0.01% | 1 | 0.26% |
| Fabio Checconi | 3 | 0.01% | 1 | 0.26% |
| Anatol Pomozov | 3 | 0.01% | 1 | 0.26% |
| Shan Wei | 3 | 0.01% | 1 | 0.26% |
| Dennis Zhou | 2 | 0.01% | 1 | 0.26% |
| Christoph Lameter | 2 | 0.01% | 1 | 0.26% |
| Joe Perches | 2 | 0.01% | 2 | 0.51% |
| Oleg Nesterov | 2 | 0.01% | 1 | 0.26% |
| Randy Dunlap | 2 | 0.01% | 1 | 0.26% |
| Andries E. Brouwer | 2 | 0.01% | 1 | 0.26% |
| Masanari Iida | 1 | 0.00% | 1 | 0.26% |
| Lucas De Marchi | 1 | 0.00% | 1 | 0.26% |
| weiping zhang | 1 | 0.00% | 1 | 0.26% |
| Kirill A. Shutemov | 1 | 0.00% | 1 | 0.26% |
| Kyungmin Park | 1 | 0.00% | 1 | 0.26% |
| Total | 20270 | 389 |
/* * 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/sched/clock.h> #include <linux/blkdev.h> #include <linux/elevator.h> #include <linux/ktime.h> #include <linux/rbtree.h> #include <linux/ioprio.h> #include <linux/blktrace_api.h> #include <linux/blk-cgroup.h> #include "blk.h" #include "blk-wbt.h" /* * tunables */ /* max queue in one round of service */ static const int cfq_quantum = 8; static const u64 cfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 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 u64 cfq_slice_sync = NSEC_PER_SEC / 10; static u64 cfq_slice_async = NSEC_PER_SEC / 25; static const int cfq_slice_async_rq = 2; static u64 cfq_slice_idle = NSEC_PER_SEC / 125; static u64 cfq_group_idle = NSEC_PER_SEC / 125; static const u64 cfq_target_latency = (u64)NSEC_PER_SEC * 3/10; /* 300 ms */ static const int cfq_hist_divisor = 4; /* * offset from end of queue service tree for idle class */ #define CFQ_IDLE_DELAY (NSEC_PER_SEC / 5) /* offset from end of group service tree under time slice mode */ #define CFQ_SLICE_MODE_GROUP_DELAY (NSEC_PER_SEC / 5) /* offset from end of group service under IOPS mode */ #define CFQ_IOPS_MODE_GROUP_DELAY (HZ / 5) /* * below this threshold, we consider thinktime immediate */ #define CFQ_MIN_TT (2 * NSEC_PER_SEC / HZ) #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 { u64 last_end_request; u64 ttime_total; u64 ttime_mean; unsigned long ttime_samples; }; /* * 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_cached rb; struct rb_node *rb_rightmost; unsigned count; u64 min_vdisktime; struct cfq_ttime ttime; }; #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT_CACHED, \ .rb_rightmost = NULL, \ .ttime = {.last_end_request = ktime_get_ns(),},} /* * 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 */ u64 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. */ u64 dispatch_start; u64 allocated_slice; u64 slice_dispatch; /* time when first request from queue completed and slice started. */ u64 slice_start; u64 slice_end; s64 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, org_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 */ u64 start_group_wait_time; u64 start_idle_time; u64 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; u64 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; u64 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 hrtimer 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_back_penalty; unsigned int cfq_back_max; unsigned int cfq_slice_async_rq; unsigned int cfq_latency; u64 cfq_fifo_expire[2]; u64 cfq_slice[2]; u64 cfq_slice_idle; u64 cfq_group_idle; u64 cfq_target_latency; /* * Fallback dummy cfqq for extreme OOM conditions */ struct cfq_queue oom_cfqq; u64 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]; } 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) { u64 now; if (!cfqg_stats_waiting(stats)) return; now = ktime_get_ns(); if (now > stats->start_group_wait_time) blkg_stat_add(&stats->group_wait_time, now - stats->start_group_wait_time); cfqg_stats_clear_waiting(stats); } /* 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 = ktime_get_ns(); cfqg_stats_mark_waiting(stats); } /* This should be called with the queue_lock held. */ static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { u64 now; if (!cfqg_stats_empty(stats)) return; now = ktime_get_ns(); if (now > stats->start_empty_time) blkg_stat_add(&stats->empty_time, now - stats->start_empty_time); cfqg_stats_clear_empty(stats); } static void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { blkg_stat_add(&cfqg->stats.dequeue, 1); } 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 = ktime_get_ns(); cfqg_stats_mark_empty(stats); } static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { struct cfqg_stats *stats = &cfqg->stats; if (cfqg_stats_idling(stats)) { u64 now = ktime_get_ns(); if (now > stats->start_idle_time) blkg_stat_add(&stats->idle_time, now - stats->start_idle_time); cfqg_stats_clear_idling(stats); } } 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 = ktime_get_ns(); cfqg_stats_mark_idling(stats); } 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); } #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) { } static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { } static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { } static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { } static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { } static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { } static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { } #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; } static struct cfq_group_data *cpd_to_cfqgd(struct blkcg_policy_data *cpd) { return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL; } static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg) { return pd_to_blkg(&cfqg->pd); } 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)); } static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg) { return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq)); } 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; } 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); } static inline void cfqg_get(struct cfq_group *cfqg) { return blkg_get(cfqg_to_blkg(cfqg)); } static inline void cfqg_put(struct cfq_group *cfqg) { return blkg_put(cfqg_to_blkg(cfqg)); } #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \ blk_add_cgroup_trace_msg((cfqd)->queue, \ cfqg_to_blkg((cfqq)->cfqg)->blkcg, \ "cfq%d%c%c " fmt, (cfqq)->pid, \ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ ##args); \ } while (0) #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \ blk_add_cgroup_trace_msg((cfqd)->queue, \ cfqg_to_blkg(cfqg)->blkcg, fmt, ##args); \ } while (0) static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, struct cfq_group *curr_cfqg, unsigned int op) { blkg_rwstat_add(&cfqg->stats.queued, op, 1); cfqg_stats_end_empty_time(&cfqg->stats); cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg); } static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, uint64_t 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 } static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, unsigned int op) { blkg_rwstat_add(&cfqg->stats.queued, op, -1); } static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, unsigned int op) { blkg_rwstat_add(&cfqg->stats.merged, op, 1); } static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, u64 start_time_ns, u64 io_start_time_ns, unsigned int op) { struct cfqg_stats *stats = &cfqg->stats; u64 now = ktime_get_ns(); if (now > io_start_time_ns) blkg_rwstat_add(&stats->service_time, op, now - io_start_time_ns); if (io_start_time_ns > start_time_ns) blkg_rwstat_add(&stats->wait_time, op, io_start_time_ns - start_time_ns); } /* @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 } /* @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 } /* * 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); } #else /* CONFIG_CFQ_GROUP_IOSCHED */ static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; } static inline bool cfqg_is_descendant(struct cfq_group *cfqg, struct cfq_group *ancestor) { return true; } static inline void cfqg_get(struct cfq_group *cfqg) { } static inline void cfqg_put(struct cfq_group *cfqg) { } #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, unsigned int op) { } static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, uint64_t time, unsigned long unaccounted_time) { } static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, unsigned int op) { } static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, unsigned int op) { } static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, u64 start_time_ns, u64 io_start_time_ns, unsigned int op) { } #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) { u64 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; } 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; } 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; } 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; } 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; } 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); } 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; } static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync) { return cic->cfqq[is_sync]; } static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq, bool is_sync) { cic->cfqq[is_sync] = cfqq; } static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic) { return cic->icq.q->elevator->elevator_data; } /* * 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); } } /* * 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 u64 cfq_prio_slice(struct cfq_data *cfqd, bool sync, unsigned short prio) { u64 base_slice = cfqd->cfq_slice[sync]; u64 slice = div_u64(base_slice, CFQ_SLICE_SCALE); WARN_ON(prio >= IOPRIO_BE_NR); return base_slice + (slice * (4 - prio)); } static inline u64 cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); } /** * 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(u64 charge, unsigned int vfraction) { u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */ /* charge / vfraction */ c <<= CFQ_SERVICE_SHIFT; return div_u64(c, vfraction); } 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; } static void update_min_vdisktime(struct cfq_rb_root *st) { if (!RB_EMPTY_ROOT(&st->rb.rb_root)) { struct cfq_group *cfqg = rb_entry_cfqg(st->rb.rb_leftmost); st->min_vdisktime = max_vdisktime(st->min_vdisktime, cfqg->vdisktime); } } /* * 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]; } static inline u64 cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) { return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT; } static inline u64 cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { u64 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)); u64 sync_slice = cfqd->cfq_slice[1]; u64 expect_latency = sync_slice * iq; u64 group_slice = cfq_group_slice(cfqd, cfqq->cfqg); if (expect_latency > group_slice) { u64 base_low_slice = 2 * cfqd->cfq_slice_idle; u64 low_slice; /* scale low_slice according to IO priority * and sync vs async */ low_slice = div64_u64(base_low_slice*slice, sync_slice); low_slice = min(slice, low_slice); /* the adapted slice value is scaled to fit all iqs * into the target latency */ slice = div64_u64(slice*group_slice, expect_latency); slice = max(slice, low_slice); } } return slice; } static inline void cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { u64 slice = cfq_scaled_cfqq_slice(cfqd, cfqq); u64 now = ktime_get_ns(); cfqq->slice_start = now; cfqq->slice_end = now + slice; cfqq->allocated_slice = slice; cfq_log_cfqq(cfqd, cfqq, "set_slice=%llu", cfqq->slice_end - now); } /* * 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 (ktime_get_ns() < cfqq->slice_end) return false; return true; } /* * 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; } } static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) { /* Service tree is empty */ if (!root->count) return NULL; return rb_entry(rb_first_cached(&root->rb), struct cfq_queue, rb_node); } static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) { return rb_entry_cfqg(rb_first_cached(&root->rb)); } static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) { if (root->rb_rightmost == n) root->rb_rightmost = rb_prev(n); rb_erase_cached(n, &root->rb); RB_CLEAR_NODE(n); --root->count; } /* * 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)); } static u64 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)); } static inline s64 cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) { return cfqg->vdisktime - st->min_vdisktime; } static void __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) { struct rb_node **node = &st->rb.rb_root.rb_node; struct rb_node *parent = NULL; struct cfq_group *__cfqg; s64 key = cfqg_key(st, cfqg); bool leftmost = true, rightmost = true; while (*node != NULL) { parent = *node; __cfqg = rb_entry_cfqg(parent); if (key < cfqg_key(st, __cfqg)) { node = &parent->rb_left; rightmost = false; } else { node = &parent->rb_right; leftmost = false; } } if (rightmost) st->rb_rightmost = &cfqg->rb_node; rb_link_node(&cfqg->rb_node, parent, node); rb_insert_color_cached(&cfqg->rb_node, &st->rb, leftmost); } /* * 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; } } 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; } } 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); } static inline u64 cfq_get_cfqg_vdisktime_delay(struct cfq_data *cfqd) { if (!iops_mode(cfqd)) return CFQ_SLICE_MODE_GROUP_DELAY; else return CFQ_IOPS_MODE_GROUP_DELAY; } 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 = st->rb_rightmost; if (n) { __cfqg = rb_entry_cfqg(n); cfqg->vdisktime = __cfqg->vdisktime + cfq_get_cfqg_vdisktime_delay(cfqd); } else cfqg->vdisktime = st->min_vdisktime; cfq_group_service_tree_add(st, cfqg); } 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); } 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); } static inline u64 cfq_cfqq_slice_usage(struct cfq_queue *cfqq, u64 *unaccounted_time) { u64 slice_used; u64 now = ktime_get_ns(); /* * Queue got expired before even a single request completed or * got expired immediately after first request completion. */ if (!cfqq->slice_start || cfqq->slice_start == now) { /* * 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(u64, (now - cfqq->dispatch_start), jiffies_to_nsecs(1)); } else { slice_used = now - cfqq->slice_start; if (slice_used > cfqq->allocated_slice) { *unaccounted_time = slice_used - cfqq->allocated_slice; slice_used = cfqq->allocated_slice; } if (cfqq->slice_start > cfqq->dispatch_start) *unaccounted_time += cfqq->slice_start - cfqq->dispatch_start; } return slice_used; } 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; u64 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; u64 now = ktime_get_ns(); 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 (cfqd->workload_expires > now) { cfqg->saved_wl_slice = cfqd->workload_expires - now; 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=%llu disp=%llu charge=%llu 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); } /** * 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 = ktime_get_ns(); } #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 } 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; } static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp) { struct cfq_group_data *cgd; cgd = kzalloc(sizeof(*cgd), gfp); if (!cgd) return NULL; return &cgd->cpd; } 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; } static void cfq_cpd_free(struct blkcg_policy_data *cpd) { kfree(cpd_to_cfqgd(cpd)); } 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)); } 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; } 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; } 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]); cfqg->async_cfqq[0][i] = NULL; } if (cfqg->async_cfqq[1][i]) { cfq_put_queue(cfqg->async_cfqq[1][i]); cfqg->async_cfqq[1][i] = NULL; } } if (cfqg->async_idle_cfqq) { cfq_put_queue(cfqg->async_idle_cfqq); cfqg->async_idle_cfqq = NULL; } /* * @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); } 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); } static void cfq_pd_reset_stats(struct blkg_policy_data *pd) { struct cfq_group *cfqg = pd_to_cfqg(pd); cfqg_stats_reset(&cfqg->stats); } 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; } static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { cfqq->cfqg = cfqg; /* cfqq reference on cfqg */ cfqg_get(cfqg); } 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); } 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; } 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); } 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; } 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; } 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; } 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; } 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); } 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); } 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; } static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, u64 val) { return __cfq_set_weight(css, val, false, false, false); } 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); } 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; } 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; } 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); } 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); } 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; } 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; } 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); } 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; } 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); } 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; } #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; } /* 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; } #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; } 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); } 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; } static inline void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { cfqq->cfqg = cfqg; } #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; u64 rb_key; struct cfq_rb_root *st; bool leftmost = true; int new_cfqq = 1; u64 now = ktime_get_ns(); st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); if (cfq_class_idle(cfqq)) { rb_key = CFQ_IDLE_DELAY; parent = st->rb_rightmost; if (parent && parent != &cfqq->rb_node) { __cfqq = rb_entry(parent, struct cfq_queue, rb_node); rb_key += __cfqq->rb_key; } else rb_key += now; } 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) + now; rb_key -= cfqq->slice_resid; cfqq->slice_resid = 0; } else { rb_key = -NSEC_PER_SEC; __cfqq = cfq_rb_first(st); rb_key += __cfqq ? __cfqq->rb_key : now; } 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; } parent = NULL; cfqq->service_tree = st; p = &st->rb.rb_root.rb_node; while (*p) { parent = *p; __cfqq = rb_entry(parent, struct cfq_queue, rb_node); /* * sort by key, that represents service time. */ if (rb_key < __cfqq->rb_key) p = &parent->rb_left; else { p = &parent->rb_right; leftmost = false; } } cfqq->rb_key = rb_key; rb_link_node(&cfqq->rb_node, parent, p); rb_insert_color_cached(&cfqq->rb_node, &st->rb, leftmost); st->count++; if (add_front || !new_cfqq) return; cfq_group_notify_queue_add(cfqd, cfqq->cfqg); } 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; } 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; } /* * 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); } } /* * 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); } /* * 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--; } /* * 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; } } } 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); } 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); } 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, op_is_sync(bio->bi_opf)); if (cfqq) return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio)); return NULL; } 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); } 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); } 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--; } } static enum elv_merge 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_bio_merge_ok(__rq, bio)) { *req = __rq; return ELEVATOR_FRONT_MERGE; } return ELEVATOR_NO_MERGE; } static void cfq_merged_request(struct request_queue *q, struct request *req, enum elv_merge type) { if (type == ELEVATOR_FRONT_MERGE) { struct cfq_queue *cfqq = RQ_CFQQ(req); cfq_reposition_rq_rb(cfqq, req); } } 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_opf); } 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) && 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); } static int cfq_allow_bio_merge(struct request_queue *q, struct request *rq, struct bio *bio) { struct cfq_data *cfqd = q->elevator->elevator_data; bool is_sync = op_is_sync(bio->bi_opf); struct cfq_io_cq *cic; struct cfq_queue *cfqq; /* * Disallow merge of a sync bio into an async request. */ if (is_sync && !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, is_sync); return cfqq == RQ_CFQQ(rq); } static int cfq_allow_rq_merge(struct request_queue *q, struct request *rq, struct request *next) { return RQ_CFQQ(rq) == RQ_CFQQ(next); } static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) { hrtimer_try_to_cancel(&cfqd->idle_slice_timer); cfqg_stats_update_idle_time(cfqq->cfqg); } 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 = ktime_get_ns(); 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; } /* * 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 - ktime_get_ns(); cfq_log_cfqq(cfqd, cfqq, "resid=%lld", 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; } } 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); } /* * 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.rb_root)) return NULL; return cfq_rb_first(st); } 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) { cfqq = cfq_rb_first(st); if (cfqq) return cfqq; } return NULL; } /* * 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; } 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); } 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; } 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; } /* * 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; } /* * 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; } 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; u64 sl, group_idle = 0; u64 now = ktime_get_ns(); /* * 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 && !cfqd->cfq_group_idle) 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 - now < cic->ttime.ttime_mean)) { cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%llu", 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; hrtimer_start(&cfqd->idle_slice_timer, ns_to_ktime(sl), HRTIMER_MODE_REL); cfqg_stats_set_start_idle_time(cfqq->cfqg); cfq_log_cfqq(cfqd, cfqq, "arm_idle: %llu group_idle: %d", sl, group_idle ? 1 : 0); } /* * 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); } /* * 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 (ktime_get_ns() < rq->fifo_time) rq = NULL; return rq; } 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); } /* * 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; } 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; } } 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; u64 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 || queue->rb_key < lowest_key)) { lowest_key = queue->rb_key; cur_best = i; key_valid = true; } } return cur_best; } static void choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) { u64 slice; unsigned count; struct cfq_rb_root *st; u64 group_slice; enum wl_class_t original_class = cfqd->serving_wl_class; u64 now = ktime_get_ns(); /* 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 = now + jiffies_to_nsecs(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 && !(now > 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 = div_u64(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) { u64 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 = div_u64(tmp, cfqd->busy_queues); slice = min_t(u64, slice, tmp); /* async workload slice is scaled down according to * the sync/async slice ratio. */ slice = div64_u64(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(u64, slice, CFQ_MIN_TT); cfq_log(cfqd, "workload slice:%llu", slice); cfqd->workload_expires = now + slice; } 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.rb_root)) return NULL; cfqg = cfq_rb_first_group(st); update_min_vdisktime(st); return cfqg; } static void cfq_choose_cfqg(struct cfq_data *cfqd) { struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); u64 now = ktime_get_ns(); cfqd->serving_group = cfqg; /* Restore the workload type data */ if (cfqg->saved_wl_slice) { cfqd->workload_expires = now + cfqg->saved_wl_slice; cfqd->serving_wl_type = cfqg->saved_wl_type; cfqd->serving_wl_class = cfqg->saved_wl_class; } else cfqd->workload_expires = now - 1; choose_wl_class_and_type(cfqd, cfqg); } /* * 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; u64 now = ktime_get_ns(); 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 (hrtimer_active(&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 - now > now - 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; } 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; } /* * 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; } static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, struct cfq_queue *cfqq) { u64 now = ktime_get_ns(); /* the queue hasn't finished any request, can't estimate */ if (cfq_cfqq_slice_new(cfqq)) return true; if (now + cfqd->cfq_slice_idle * cfqq->dispatched > cfqq->slice_end) return true; return false; } static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) { unsigned int max_dispatch; if (cfq_cfqq_must_dispatch(cfqq)) return true; /* * 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) { u64 last_sync = ktime_get_ns() - cfqd->last_delayed_sync; unsigned int depth; depth = div64_u64(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; } /* * 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)); rq = cfq_check_fifo(cfqq); if (rq) cfq_mark_cfqq_must_dispatch(cfqq); if (!cfq_may_dispatch(cfqd, cfqq)) return false; /* * follow expired path, else get first next available */ if (!rq) rq = cfqq->next_rq; else cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", 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; } /* * 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 = ktime_get_ns() + 1; cfq_slice_expired(cfqd, 0); } cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); return 1; } /* * 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); } 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; } } 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); } static void cfq_init_icq(struct io_cq *icq) { struct cfq_io_cq *cic = icq_to_cic(icq); cic->ttime.last_end_request = ktime_get_ns(); } 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); } } 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); /* fall through */ 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; cfqq->org_ioprio_class = cfqq->ioprio_class; cfq_clear_cfqq_prio_changed(cfqq); } 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; } 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; } #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; } #else static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { } #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(); } } 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 | __GFP_NOWARN, cfqd->queue->node); if (!cfqq) { cfqq = &cfqd->oom_cfqq; goto out; } /* cfq_init_cfqq() assumes cfqq->ioprio_class is initialized. */ cfqq->ioprio_class = IOPRIO_CLASS_NONE; 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; } static void __cfq_update_io_thinktime(struct cfq_ttime *ttime, u64 slice_idle) { u64 elapsed = ktime_get_ns() - ttime->last_end_request; elapsed = min(elapsed, 2UL * slice_idle); ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed, 8); ttime->ttime_mean = div64_ul(ttime->ttime_total + 128, ttime->ttime_samples); } 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 } 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); } static inline bool req_noidle(struct request *req) { return req_op(req) == REQ_OP_WRITE && (req->cmd_flags & (REQ_SYNC | REQ_IDLE)) == REQ_SYNC; } /* * 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 && req_noidle(cfqq->next_rq)) 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); } } /* * 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) && !cfq_cfqq_must_dispatch(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; } /* * 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); } /* * 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); } } 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 = ktime_get_ns() + 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); } /* * 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; } static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) { struct cfq_io_cq *cic = cfqd->active_cic; u64 now = ktime_get_ns(); /* 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 - now < 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 - now <= jiffies_to_nsecs(1)) return true; return false; } 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); u64 now = ktime_get_ns(); cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", req_noidle(rq)); 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->io_start_time_ns, 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 (rq->start_time_ns + 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)) { u64 extend_sl = cfqd->cfq_slice_idle; if (!cfqd->cfq_slice_idle) extend_sl = cfqd->cfq_group_idle; cfqq->slice_end = now + 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); } static void cfqq_boost_on_prio(struct cfq_queue *cfqq, unsigned int op) { /* * If REQ_PRIO is set, boost class and prio level, if it's below * BE/NORM. If prio is not set, restore the potentially boosted * class/prio level. */ if (!(op & REQ_PRIO)) { cfqq->ioprio_class = cfqq->org_ioprio_class; cfqq->ioprio = cfqq->org_ioprio; } else { if (cfq_class_idle(cfqq)) cfqq->ioprio_class = IOPRIO_CLASS_BE; if (cfqq->ioprio > IOPRIO_NORM) cfqq->ioprio = IOPRIO_NORM; } } 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; } static int cfq_may_queue(struct request_queue *q, unsigned int op) { 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, op_is_sync(op)); if (cfqq) { cfq_init_prio_data(cfqq, cic); cfqq_boost_on_prio(cfqq, op); return __cfq_may_queue(cfqq); } return ELV_MQUEUE_MAY; } /* * 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); } } 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); } /* * 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; } /* * 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; } 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); } /* * Timer running if the active_queue is currently idling inside its time slice */ static enum hrtimer_restart cfq_idle_slice_timer(struct hrtimer *timer) { struct cfq_data *cfqd = container_of(timer, struct cfq_data, idle_slice_timer); 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); return HRTIMER_NORESTART; } static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) { hrtimer_cancel(&cfqd->idle_slice_timer); cancel_work_sync(&cfqd->unplug_work); } 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); } 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); hrtimer_init(&cfqd->idle_slice_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); cfqd->idle_slice_timer.function = cfq_idle_slice_timer; 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 = ktime_get_ns() - NSEC_PER_SEC; return 0; out_free: kfree(cfqd); kobject_put(&eq->kobj); return ret; } 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; wbt_disable_default(q); } /* * sysfs parts below --> */ static ssize_t cfq_var_show(unsigned int var, char *page) { return sprintf(page, "%u\n", var); } static void cfq_var_store(unsigned int *var, const char *page) { char *p = (char *) page; *var = simple_strtoul(p, &p, 10); } #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ static ssize_t __FUNC(struct elevator_queue *e, char *page) \ { \ struct cfq_data *cfqd = e->elevator_data; \ u64 __data = __VAR; \ if (__CONV) \ __data = div_u64(__data, NSEC_PER_MSEC); \ 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 USEC_SHOW_FUNCTION(__FUNC, __VAR) \ static ssize_t __FUNC(struct elevator_queue *e, char *page) \ { \ struct cfq_data *cfqd = e->elevator_data; \ u64 __data = __VAR; \ __data = div_u64(__data, NSEC_PER_USEC); \ return cfq_var_show(__data, (page)); \ } USEC_SHOW_FUNCTION(cfq_slice_idle_us_show, cfqd->cfq_slice_idle); USEC_SHOW_FUNCTION(cfq_group_idle_us_show, cfqd->cfq_group_idle); USEC_SHOW_FUNCTION(cfq_slice_sync_us_show, cfqd->cfq_slice[1]); USEC_SHOW_FUNCTION(cfq_slice_async_us_show, cfqd->cfq_slice[0]); USEC_SHOW_FUNCTION(cfq_target_latency_us_show, cfqd->cfq_target_latency); #undef USEC_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, __min = (MIN), __max = (MAX); \ \ cfq_var_store(&__data, (page)); \ if (__data < __min) \ __data = __min; \ else if (__data > __max) \ __data = __max; \ if (__CONV) \ *(__PTR) = (u64)__data * NSEC_PER_MSEC; \ else \ *(__PTR) = __data; \ return count; \ } 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 USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ { \ struct cfq_data *cfqd = e->elevator_data; \ unsigned int __data, __min = (MIN), __max = (MAX); \ \ cfq_var_store(&__data, (page)); \ if (__data < __min) \ __data = __min; \ else if (__data > __max) \ __data = __max; \ *(__PTR) = (u64)__data * NSEC_PER_USEC; \ return count; \ } USEC_STORE_FUNCTION(cfq_slice_idle_us_store, &cfqd->cfq_slice_idle, 0, UINT_MAX); USEC_STORE_FUNCTION(cfq_group_idle_us_store, &cfqd->cfq_group_idle, 0, UINT_MAX); USEC_STORE_FUNCTION(cfq_slice_sync_us_store, &cfqd->cfq_slice[1], 1, UINT_MAX); USEC_STORE_FUNCTION(cfq_slice_async_us_store, &cfqd->cfq_slice[0], 1, UINT_MAX); USEC_STORE_FUNCTION(cfq_target_latency_us_store, &cfqd->cfq_target_latency, 1, UINT_MAX); #undef USEC_STORE_FUNCTION #define CFQ_ATTR(name) \ __ATTR(name, 0644, 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_sync_us), CFQ_ATTR(slice_async), CFQ_ATTR(slice_async_us), CFQ_ATTR(slice_async_rq), CFQ_ATTR(slice_idle), CFQ_ATTR(slice_idle_us), CFQ_ATTR(group_idle), CFQ_ATTR(group_idle_us), CFQ_ATTR(low_latency), CFQ_ATTR(target_latency), CFQ_ATTR(target_latency_us), __ATTR_NULL }; static struct elevator_type iosched_cfq = { .ops.sq = { .elevator_merge_fn = cfq_merge, .elevator_merged_fn = cfq_merged_request, .elevator_merge_req_fn = cfq_merged_requests, .elevator_allow_bio_merge_fn = cfq_allow_bio_merge, .elevator_allow_rq_merge_fn = cfq_allow_rq_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; #ifdef CONFIG_CFQ_GROUP_IOSCHED 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; } 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); } module_init(cfq_init); module_exit(cfq_exit); MODULE_AUTHOR("Jens Axboe"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler");
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