cregit-Linux how code gets into the kernel

Release 4.7 block/elevator.c

Directory: block
/*
 *  Block device elevator/IO-scheduler.
 *
 *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
 *
 * 30042000 Jens Axboe <axboe@kernel.dk> :
 *
 * Split the elevator a bit so that it is possible to choose a different
 * one or even write a new "plug in". There are three pieces:
 * - elevator_fn, inserts a new request in the queue list
 * - elevator_merge_fn, decides whether a new buffer can be merged with
 *   an existing request
 * - elevator_dequeue_fn, called when a request is taken off the active list
 *
 * 20082000 Dave Jones <davej@suse.de> :
 * Removed tests for max-bomb-segments, which was breaking elvtune
 *  when run without -bN
 *
 * Jens:
 * - Rework again to work with bio instead of buffer_heads
 * - loose bi_dev comparisons, partition handling is right now
 * - completely modularize elevator setup and teardown
 *
 */
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/compiler.h>
#include <linux/blktrace_api.h>
#include <linux/hash.h>
#include <linux/uaccess.h>
#include <linux/pm_runtime.h>
#include <linux/blk-cgroup.h>

#include <trace/events/block.h>

#include "blk.h"

static DEFINE_SPINLOCK(elv_list_lock);
static LIST_HEAD(elv_list);

/*
 * Merge hash stuff.
 */

#define rq_hash_key(rq)		(blk_rq_pos(rq) + blk_rq_sectors(rq))

/*
 * Query io scheduler to see if the current process issuing bio may be
 * merged with rq.
 */

static int elv_iosched_allow_merge(struct request *rq, struct bio *bio) { struct request_queue *q = rq->q; struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_allow_merge_fn) return e->type->ops.elevator_allow_merge_fn(q, rq, bio); return 1; }

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tejun heotejun heo69.52%125.00%
Total63100.00%4100.00%

/* * can we safely merge with this request? */
bool elv_rq_merge_ok(struct request *rq, struct bio *bio) { if (!blk_rq_merge_ok(rq, bio)) return 0; if (!elv_iosched_allow_merge(rq, bio)) return 0; return 1; }

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jens axboejens axboe1329.55%116.67%
martin k. petersenmartin k. petersen49.09%116.67%
tejun heotejun heo36.82%116.67%
Total44100.00%6100.00%

EXPORT_SYMBOL(elv_rq_merge_ok);
static struct elevator_type *elevator_find(const char *name) { struct elevator_type *e; list_for_each_entry(e, &elv_list, list) { if (!strcmp(e->elevator_name, name)) return e; } return NULL; }

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vasily tarasovvasily tarasov48.70%125.00%
matthias kaehlckematthias kaehlcke48.70%125.00%
adrian bunkadrian bunk12.17%125.00%
Total46100.00%4100.00%


static void elevator_put(struct elevator_type *e) { module_put(e->elevator_owner); }

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Total18100.00%1100.00%


static struct elevator_type *elevator_get(const char *name, bool try_loading) { struct elevator_type *e; spin_lock(&elv_list_lock); e = elevator_find(name); if (!e && try_loading) { spin_unlock(&elv_list_lock); request_module("%s-iosched", name); spin_lock(&elv_list_lock); e = elevator_find(name); } if (e && !try_module_get(e->elevator_owner)) e = NULL; spin_unlock(&elv_list_lock); return e; }

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tejun heotejun heo2324.47%228.57%
kees cookkees cook11.06%114.29%
wzt wztwzt wzt11.06%114.29%
Total94100.00%7100.00%

static char chosen_elevator[ELV_NAME_MAX];
static int __init elevator_setup(char *str) { /* * Be backwards-compatible with previous kernels, so users * won't get the wrong elevator. */ strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); return 1; }

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nate diller*nate diller*620.69%114.29%
pre-gitpre-git26.90%114.29%
linus torvaldslinus torvalds26.90%114.29%
chuck ebbertchuck ebbert13.45%114.29%
hirofumi ogawahirofumi ogawa13.45%114.29%
Total29100.00%7100.00%

__setup("elevator=", elevator_setup); /* called during boot to load the elevator chosen by the elevator param */
void __init load_default_elevator_module(void) { struct elevator_type *e; if (!chosen_elevator[0]) return; spin_lock(&elv_list_lock); e = elevator_find(chosen_elevator); spin_unlock(&elv_list_lock); if (!e) request_module("%s-iosched", chosen_elevator); }

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static struct kobj_type elv_ktype;
struct elevator_queue *elevator_alloc(struct request_queue *q, struct elevator_type *e) { struct elevator_queue *eq; eq = kzalloc_node(sizeof(*eq), GFP_KERNEL, q->node); if (unlikely(!eq)) return NULL; eq->type = e; kobject_init(&eq->kobj, &elv_ktype); mutex_init(&eq->sysfs_lock); hash_init(eq->hash); return eq; }

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al viroal viro4451.76%18.33%
jens axboejens axboe3237.65%433.33%
greg kroah-hartmangreg kroah-hartman33.53%325.00%
chao yuchao yu33.53%18.33%
joe perchesjoe perches11.18%18.33%
tejun heotejun heo11.18%18.33%
sasha levinsasha levin11.18%18.33%
Total85100.00%12100.00%

EXPORT_SYMBOL(elevator_alloc);
static void elevator_release(struct kobject *kobj) { struct elevator_queue *e; e = container_of(kobj, struct elevator_queue, kobj); elevator_put(e->type); kfree(e); }

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al viroal viro3177.50%133.33%
jens axboejens axboe820.00%133.33%
tejun heotejun heo12.50%133.33%
Total40100.00%3100.00%


int elevator_init(struct request_queue *q, char *name) { struct elevator_type *e = NULL; int err; /* * q->sysfs_lock must be held to provide mutual exclusion between * elevator_switch() and here. */ lockdep_assert_held(&q->sysfs_lock); if (unlikely(q->elevator)) return 0; INIT_LIST_HEAD(&q->queue_head); q->last_merge = NULL; q->end_sector = 0; q->boundary_rq = NULL; if (name) { e = elevator_get(name, true); if (!e) return -EINVAL; } /* * Use the default elevator specified by config boot param or * config option. Don't try to load modules as we could be running * off async and request_module() isn't allowed from async. */ if (!e && *chosen_elevator) { e = elevator_get(chosen_elevator, false); if (!e) printk(KERN_ERR "I/O scheduler %s not found\n", chosen_elevator); } if (!e) { e = elevator_get(CONFIG_DEFAULT_IOSCHED, false); if (!e) { printk(KERN_ERR "Default I/O scheduler not found. " \ "Using noop.\n"); e = elevator_get("noop", false); } } err = e->ops.elevator_init_fn(q, e); if (err) elevator_put(e); return err; }

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nate diller*nate diller*4724.35%212.50%
tejun heotejun heo4322.28%425.00%
mike snitzermike snitzer126.22%16.25%
linus torvaldslinus torvalds126.22%16.25%
sudip mukherjeesudip mukherjee105.18%16.25%
tomoki sekiyamatomoki sekiyama94.66%16.25%
ma jianpengma jianpeng21.04%16.25%
Total193100.00%16100.00%

EXPORT_SYMBOL(elevator_init);
void elevator_exit(struct elevator_queue *e) { mutex_lock(&e->sysfs_lock); if (e->type->ops.elevator_exit_fn) e->type->ops.elevator_exit_fn(e); mutex_unlock(&e->sysfs_lock); kobject_put(&e->kobj); }

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jens axboejens axboe3258.18%250.00%
al viroal viro1730.91%125.00%
tejun heotejun heo610.91%125.00%
Total55100.00%4100.00%

EXPORT_SYMBOL(elevator_exit);
static inline void __elv_rqhash_del(struct request *rq) { hash_del(&rq->hash); rq->cmd_flags &= ~REQ_HASHED; }

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sasha levinsasha levin13.70%133.33%
Total27100.00%3100.00%


static void elv_rqhash_del(struct request_queue *q, struct request *rq) { if (ELV_ON_HASH(rq)) __elv_rqhash_del(rq); }

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static void elv_rqhash_add(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; BUG_ON(ELV_ON_HASH(rq)); hash_add(e->hash, &rq->hash, rq_hash_key(rq)); rq->cmd_flags |= REQ_HASHED; }

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jens axboejens axboe5292.86%480.00%
sasha levinsasha levin47.14%120.00%
Total56100.00%5100.00%


static void elv_rqhash_reposition(struct request_queue *q, struct request *rq) { __elv_rqhash_del(rq); elv_rqhash_add(q, rq); }

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static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset) { struct elevator_queue *e = q->elevator; struct hlist_node *next; struct request *rq; hash_for_each_possible_safe(e->hash, rq, next, hash, offset) { BUG_ON(!ELV_ON_HASH(rq)); if (unlikely(!rq_mergeable(rq))) { __elv_rqhash_del(rq); continue; } if (rq_hash_key(rq) == offset) return rq; } return NULL; }

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sasha levinsasha levin55.43%125.00%
Total92100.00%4100.00%

/* * RB-tree support functions for inserting/lookup/removal of requests * in a sorted RB tree. */
void elv_rb_add(struct rb_root *root, struct request *rq) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; struct request *__rq; while (*p) { parent = *p; __rq = rb_entry(parent, struct request, rb_node); if (blk_rq_pos(rq) < blk_rq_pos(__rq)) p = &(*p)->rb_left; else if (blk_rq_pos(rq) >= blk_rq_pos(__rq)) p = &(*p)->rb_right; } rb_link_node(&rq->rb_node, parent, p); rb_insert_color(&rq->rb_node, root); }

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jens axboejens axboe11589.15%133.33%
tejun heotejun heo129.30%133.33%
jeff moyerjeff moyer21.55%133.33%
Total129100.00%3100.00%

EXPORT_SYMBOL(elv_rb_add);
void elv_rb_del(struct rb_root *root, struct request *rq) { BUG_ON(RB_EMPTY_NODE(&rq->rb_node)); rb_erase(&rq->rb_node, root); RB_CLEAR_NODE(&rq->rb_node); }

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EXPORT_SYMBOL(elv_rb_del);
struct request *elv_rb_find(struct rb_root *root, sector_t sector) { struct rb_node *n = root->rb_node; struct request *rq; while (n) { rq = rb_entry(n, struct request, rb_node); if (sector < blk_rq_pos(rq)) n = n->rb_left; else if (sector > blk_rq_pos(rq)) n = n->rb_right; else return rq; } return NULL; }

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jens axboejens axboe7992.94%150.00%
tejun heotejun heo67.06%150.00%
Total85100.00%2100.00%

EXPORT_SYMBOL(elv_rb_find); /* * Insert rq into dispatch queue of q. Queue lock must be held on * entry. rq is sort instead into the dispatch queue. To be used by * specific elevators. */
void elv_dispatch_sort(struct request_queue *q, struct request *rq) { sector_t boundary; struct list_head *entry; int stop_flags; if (q->last_merge == rq) q->last_merge = NULL; elv_rqhash_del(q, rq); q->nr_sorted--; boundary = q->end_sector; stop_flags = REQ_SOFTBARRIER | REQ_STARTED; list_for_each_prev(entry, &q->queue_head) { struct request *pos = list_entry_rq(entry); if ((rq->cmd_flags & REQ_DISCARD) != (pos->cmd_flags & REQ_DISCARD)) break; if (rq_data_dir(rq) != rq_data_dir(pos)) break; if (pos->cmd_flags & stop_flags) break; if (blk_rq_pos(rq) >= boundary) { if (blk_rq_pos(pos) < boundary) continue; } else { if (blk_rq_pos(pos) >= boundary) break; } if (blk_rq_pos(rq) >= blk_rq_pos(pos)) break; } list_add(&rq->queuelist, entry); }

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jens axboejens axboe3519.44%650.00%
christoph hellwigchristoph hellwig126.67%18.33%
david woodhousedavid woodhouse73.89%18.33%
Total180100.00%12100.00%

EXPORT_SYMBOL(elv_dispatch_sort); /* * Insert rq into dispatch queue of q. Queue lock must be held on * entry. rq is added to the back of the dispatch queue. To be used by * specific elevators. */
void elv_dispatch_add_tail(struct request_queue *q, struct request *rq) { if (q->last_merge == rq) q->last_merge = NULL; elv_rqhash_del(q, rq); q->nr_sorted--; q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; list_add_tail(&rq->queuelist, &q->queue_head); }

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EXPORT_SYMBOL(elv_dispatch_add_tail);
int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) { struct elevator_queue *e = q->elevator; struct request *__rq; int ret; /* * Levels of merges: * nomerges: No merges at all attempted * noxmerges: Only simple one-hit cache try * merges: All merge tries attempted */ if (blk_queue_nomerges(q) || !bio_mergeable(bio)) return ELEVATOR_NO_MERGE; /* * First try one-hit cache. */ if (q->last_merge && elv_rq_merge_ok(q->last_merge, bio)) { ret = blk_try_merge(q->last_merge, bio); if (ret != ELEVATOR_NO_MERGE) { *req = q->last_merge; return ret; } } if (blk_queue_noxmerges(q)) return ELEVATOR_NO_MERGE; /* * See if our hash lookup can find a potential backmerge. */ __rq = elv_rqhash_find(q, bio->bi_iter.bi_sector); if (__rq && elv_rq_merge_ok(__rq, bio)) { *req = __rq; return ELEVATOR_BACK_MERGE; } if (e->type->ops.elevator_merge_fn) return e->type->ops.elevator_merge_fn(q, req, bio); return ELEVATOR_NO_MERGE; }

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jens axboejens axboe7643.18%538.46%
tejun heotejun heo5531.25%323.08%
alan d. brunellealan d. brunelle2111.93%215.38%
linus torvaldslinus torvalds169.09%17.69%
ming leiming lei63.41%17.69%
kent overstreetkent overstreet21.14%17.69%
Total176100.00%13100.00%

/* * Attempt to do an insertion back merge. Only check for the case where * we can append 'rq' to an existing request, so we can throw 'rq' away * afterwards. * * Returns true if we merged, false otherwise */
static bool elv_attempt_insert_merge(struct request_queue *q, struct request *rq) { struct request *__rq; bool ret; if (blk_queue_nomerges(q)) return false; /* * First try one-hit cache. */ if (q->last_merge && blk_attempt_req_merge(q, q->last_merge, rq)) return true; if (blk_queue_noxmerges(q)) return false; ret = false; /* * See if our hash lookup can find a potential backmerge. */ while (1) { __rq = elv_rqhash_find(q, blk_rq_pos(rq)); if (!__rq || !blk_attempt_req_merge(q, __rq, rq)) break; /* The merged request could be merged with others, try again */ ret = true; rq = __rq; } return ret; }

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jens axboejens axboe9077.59%150.00%
shaohua lishaohua li2622.41%150.00%
Total116100.00%2100.00%


void elv_merged_request(struct request_queue *q, struct request *rq, int type) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_merged_fn) e->type->ops.elevator_merged_fn(q, rq, type); if (type == ELEVATOR_BACK_MERGE) elv_rqhash_reposition(q, rq); q->last_merge = rq; }

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jens axboejens axboe5983.10%675.00%
tejun heotejun heo1216.90%225.00%
Total71100.00%8100.00%


void elv_merge_requests(struct request_queue *q, struct request *rq, struct request *next) { struct elevator_queue *e = q->elevator; const int next_sorted = next->cmd_flags & REQ_SORTED; if (next_sorted && e->type->ops.elevator_merge_req_fn) e->type->ops.elevator_merge_req_fn(q, rq, next); elv_rqhash_reposition(q, rq); if (next_sorted) { elv_rqhash_del(q, next); q->nr_sorted--; } q->last_merge = rq; }

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jens axboejens axboe4041.24%660.00%
tejun heotejun heo1717.53%330.00%
Total97100.00%10100.00%


void elv_bio_merged(struct request_queue *q, struct request *rq, struct bio *bio) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_bio_merged_fn) e->type->ops.elevator_bio_merged_fn(q, rq, bio); }

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divyesh shahdivyesh shah4888.89%150.00%
tejun heotejun heo611.11%150.00%
Total54100.00%2100.00%

#ifdef CONFIG_PM
static void blk_pm_requeue_request(struct request *rq) { if (rq->q->dev && !(rq->cmd_flags & REQ_PM)) rq->q->nr_pending--; }

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static void blk_pm_add_request(struct request_queue *q, struct request *rq) { if (q->dev && !(rq->cmd_flags & REQ_PM) && q->nr_pending++ == 0 && (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING)) pm_request_resume(q->dev); }

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#else
static inline void blk_pm_requeue_request(struct request *rq) {}

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static inline void blk_pm_add_request(struct request_queue *q, struct request *rq) { }

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#endif
void elv_requeue_request(struct request_queue *q, struct request *rq) { /* * it already went through dequeue, we need to decrement the * in_flight count again */ if (blk_account_rq(rq)) { q->in_flight[rq_is_sync(rq)]--; if (rq->cmd_flags & REQ_SORTED) elv_deactivate_rq(q, rq); } rq->cmd_flags &= ~REQ_STARTED; blk_pm_requeue_request(rq); __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE); }

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jens axboejens axboe4258.33%758.33%
andrew mortonandrew morton1318.06%18.33%
tejun heotejun heo811.11%216.67%
lin minglin ming56.94%18.33%
christoph hellwigchristoph hellwig45.56%18.33%
Total72100.00%12100.00%


void elv_drain_elevator(struct request_queue *q) { static int printed; lockdep_assert_held(q->queue_lock); while (q->elevator->type->ops.elevator_dispatch_fn(q, 1)) ; if (q->nr_sorted && printed++ < 10) { printk(KERN_ERR "%s: forced dispatching is broken " "(nr_sorted=%u), please report this\n", q->elevator->type->elevator_name, q->nr_sorted); } }

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tejun heotejun heo6997.18%375.00%
jens axboejens axboe22.82%125.00%
Total71100.00%4100.00%


void __elv_add_request(struct request_queue *q, struct request *rq, int where) { trace_block_rq_insert(q, rq); blk_pm_add_request(q, rq); rq->q = q; if (rq->cmd_flags & REQ_SOFTBARRIER) { /* barriers are scheduling boundary, update end_sector */ if (rq->cmd_type == REQ_TYPE_FS) { q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; } } else if (!(rq->cmd_flags & REQ_ELVPRIV) && (where == ELEVATOR_INSERT_SORT || where == ELEVATOR_INSERT_SORT_MERGE)) where = ELEVATOR_INSERT_BACK; switch (where) { case ELEVATOR_INSERT_REQUEUE: case ELEVATOR_INSERT_FRONT: rq->cmd_flags |= REQ_SOFTBARRIER; list_add(&rq->queuelist, &q->queue_head); break; case ELEVATOR_INSERT_BACK: rq->cmd_flags |= REQ_SOFTBARRIER; elv_drain_elevator(q); list_add_tail(&rq->queuelist, &q->queue_head); /* * We kick the queue here for the following reasons. * - The elevator might have returned NULL previously * to delay requests and returned them now. As the * queue wasn't empty before this request, ll_rw_blk * won't run the queue on return, resulting in hang. * - Usually, back inserted requests won't be merged * with anything. There's no point in delaying queue * processing. */ __blk_run_queue(q); break; case ELEVATOR_INSERT_SORT_MERGE: /* * If we succeed in merging this request with one in the * queue already, we are done - rq has now been freed, * so no need to do anything further. */ if (elv_attempt_insert_merge(q, rq)) break; case ELEVATOR_INSERT_SORT: BUG_ON(rq->cmd_type != REQ_TYPE_FS); rq->cmd_flags |= REQ_SORTED; q->nr_sorted++; if (rq_mergeable(rq)) { elv_rqhash_add(q, rq); if (!q->last_merge) q->last_merge = rq; } /* * Some ioscheds (cfq) run q->request_fn directly, so * rq cannot be accessed after calling * elevator_add_req_fn. */ q->elevator->type->ops.elevator_add_req_fn(q, rq); break; case ELEVATOR_INSERT_FLUSH: rq->cmd_flags |= REQ_SOFTBARRIER; blk_insert_flush(rq); break; default: printk(KERN_ERR "%s: bad insertion point %d\n", __func__, where); BUG(); } }

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tejun heotejun heo12946.40%936.00%
jens axboejens axboe12043.17%1040.00%
linus torvaldslinus torvalds155.40%14.00%
lin minglin ming72.52%14.00%
christoph hellwigchristoph hellwig41.44%14.00%
harvey harrisonharvey harrison10.36%14.00%
arnaldo carvalho de meloarnaldo carvalho de melo10.36%14.00%
andrew mortonandrew morton10.36%14.00%
Total278100.00%25100.00%

EXPORT_SYMBOL(__elv_add_request);
void elv_add_request(struct request_queue *q, struct request *rq, int where) { unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); __elv_add_request(q, rq, where); spin_unlock_irqrestore(q->queue_lock, flags); }

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jens axboejens axboe4693.88%375.00%
linus torvaldslinus torvalds36.12%125.00%
Total49100.00%4100.00%

EXPORT_SYMBOL(elv_add_request);
struct request *elv_latter_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_latter_req_fn) return e->type->ops.elevator_latter_req_fn(q, rq); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe4788.68%685.71%
tejun heotejun heo611.32%114.29%
Total53100.00%7100.00%


struct request *elv_former_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_former_req_fn) return e->type->ops.elevator_former_req_fn(q, rq); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe4788.68%685.71%
tejun heotejun heo611.32%114.29%
Total53100.00%7100.00%


int elv_set_request(struct request_queue *q, struct request *rq, struct bio *bio, gfp_t gfp_mask) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_set_req_fn) return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe4977.78%457.14%
tejun heotejun heo1320.63%228.57%
al viroal viro11.59%114.29%
Total63100.00%7100.00%


void elv_put_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_put_req_fn) e->type->ops.elevator_put_req_fn(rq); }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe3986.67%480.00%
tejun heotejun heo613.33%120.00%
Total45100.00%5100.00%


int elv_may_queue(struct request_queue *q, int rw) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_may_queue_fn) return e->type->ops.elevator_may_queue_fn(q, rw); return ELV_MQUEUE_MAY; }

Contributors

PersonTokensPropCommitsCommitProp
andrew mortonandrew morton3673.47%116.67%
jens axboejens axboe714.29%466.67%
tejun heotejun heo612.24%116.67%
Total49100.00%6100.00%


void elv_completed_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; /* * request is released from the driver, io must be done */ if (blk_account_rq(rq)) { q->in_flight[rq_is_sync(rq)]--; if ((rq->cmd_flags & REQ_SORTED) && e->type->ops.elevator_completed_req_fn) e->type->ops.elevator_completed_req_fn(q, rq); } }

Contributors

PersonTokensPropCommitsCommitProp
tejun heotejun heo3343.42%333.33%
andrew mortonandrew morton2735.53%222.22%
jens axboejens axboe1013.16%333.33%
christoph hellwigchristoph hellwig67.89%111.11%
Total76100.00%9100.00%

#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
static ssize_t elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page) { struct elv_fs_entry *entry = to_elv(attr); struct elevator_queue *e; ssize_t error; if (!entry->show) return -EIO; e = container_of(kobj, struct elevator_queue, kobj); mutex_lock(&e->sysfs_lock); error = e->type ? entry->show(e, page) : -ENOENT; mutex_unlock(&e->sysfs_lock); return error; }

Contributors

PersonTokensPropCommitsCommitProp
al viroal viro6970.41%125.00%
jens axboejens axboe2828.57%250.00%
tejun heotejun heo11.02%125.00%
Total98100.00%4100.00%


static ssize_t elv_attr_store(struct kobject *kobj, struct attribute *attr, const char *page, size_t length) { struct elv_fs_entry *entry = to_elv(attr); struct elevator_queue *e; ssize_t error; if (!entry->store) return -EIO; e = container_of(kobj, struct elevator_queue, kobj); mutex_lock(&e->sysfs_lock); error = e->type ? entry->store(e, page, length) : -ENOENT; mutex_unlock(&e->sysfs_lock); return error; }

Contributors

PersonTokensPropCommitsCommitProp
al viroal viro7168.27%125.00%
jens axboejens axboe3230.77%250.00%
tejun heotejun heo10.96%125.00%
Total104100.00%4100.00%

static const struct sysfs_ops elv_sysfs_ops = { .show = elv_attr_show, .store = elv_attr_store, }; static struct kobj_type elv_ktype = { .sysfs_ops = &elv_sysfs_ops, .release = elevator_release, };
int elv_register_queue(struct request_queue *q) { struct elevator_queue *e = q->elevator; int error; error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched"); if (!error) { struct elv_fs_entry *attr = e->type->elevator_attrs; if (attr) { while (attr->attr.name) { if (sysfs_create_file(&e->kobj, &attr->attr)) break; attr++; } } kobject_uevent(&e->kobj, KOBJ_ADD); e->registered = 1; if (e->type->ops.elevator_registered_fn) e->type->ops.elevator_registered_fn(q); } return error; }

Contributors

PersonTokensPropCommitsCommitProp
al viroal viro7555.97%218.18%
jens axboejens axboe4029.85%545.45%
greg kroah-hartmangreg kroah-hartman107.46%218.18%
tejun heotejun heo96.72%218.18%
Total134100.00%11100.00%

EXPORT_SYMBOL(elv_register_queue);
void elv_unregister_queue(struct request_queue *q) { if (q) { struct elevator_queue *e = q->elevator; kobject_uevent(&e->kobj, KOBJ_REMOVE); kobject_del(&e->kobj); e->registered = 0; } }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe2653.06%457.14%
tejun heotejun heo1734.69%114.29%
al viroal viro510.20%114.29%
patrick mochelpatrick mochel12.04%114.29%
Total49100.00%7100.00%

EXPORT_SYMBOL(elv_unregister_queue);
int elv_register(struct elevator_type *e) { char *def = ""; /* create icq_cache if requested */ if (e->icq_size) { if (WARN_ON(e->icq_size < sizeof(struct io_cq)) || WARN_ON(e->icq_align < __alignof__(struct io_cq))) return -EINVAL; snprintf(e->icq_cache_name, sizeof(e->icq_cache_name), "%s_io_cq", e->elevator_name); e->icq_cache = kmem_cache_create(e->icq_cache_name, e->icq_size, e->icq_align, 0, NULL); if (!e->icq_cache) return -ENOMEM; } /* register, don't allow duplicate names */ spin_lock(&elv_list_lock); if (elevator_find(e->elevator_name)) { spin_unlock(&elv_list_lock); if (e->icq_cache) kmem_cache_destroy(e->icq_cache); return -EBUSY; } list_add_tail(&e->list, &elv_list); spin_unlock(&elv_list_lock); /* print pretty message */ if (!strcmp(e->elevator_name, chosen_elevator) || (!*chosen_elevator && !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) def = " (default)"; printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, def); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
tejun heotejun heo13260.83%225.00%
jens axboejens axboe5223.96%337.50%
nate diller*nate diller*167.37%112.50%
thibaut varenethibaut varene167.37%112.50%
eric sesterhenneric sesterhenn10.46%112.50%
Total217100.00%8100.00%

EXPORT_SYMBOL_GPL(elv_register);
void elv_unregister(struct elevator_type *e) { /* unregister */ spin_lock(&elv_list_lock); list_del_init(&e->list); spin_unlock(&elv_list_lock); /* * Destroy icq_cache if it exists. icq's are RCU managed. Make * sure all RCU operations are complete before proceeding. */ if (e->icq_cache) { rcu_barrier(); kmem_cache_destroy(e->icq_cache); e->icq_cache = NULL; } }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe3053.57%266.67%
tejun heotejun heo2646.43%133.33%
Total56100.00%3100.00%

EXPORT_SYMBOL_GPL(elv_unregister); /* * switch to new_e io scheduler. be careful not to introduce deadlocks - * we don't free the old io scheduler, before we have allocated what we * need for the new one. this way we have a chance of going back to the old * one, if the new one fails init for some reason. */
static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) { struct elevator_queue *old = q->elevator; bool registered = old->registered; int err; /* * Turn on BYPASS and drain all requests w/ elevator private data. * Block layer doesn't call into a quiesced elevator - all requests * are directly put on the dispatch list without elevator data * using INSERT_BACK. All requests have SOFTBARRIER set and no * merge happens either. */ blk_queue_bypass_start(q); /* unregister and clear all auxiliary data of the old elevator */ if (registered) elv_unregister_queue(q); spin_lock_irq(q->queue_lock); ioc_clear_queue(q); spin_unlock_irq(q->queue_lock); /* allocate, init and register new elevator */ err = new_e->ops.elevator_init_fn(q, new_e); if (err) goto fail_init; if (registered) { err = elv_register_queue(q); if (err) goto fail_register; } /* done, kill the old one and finish */ elevator_exit(old); blk_queue_bypass_end(q); blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name); return 0; fail_register: elevator_exit(q->elevator); fail_init: /* switch failed, restore and re-register old elevator */ q->elevator = old; elv_register_queue(q); blk_queue_bypass_end(q); return err; }

Contributors

PersonTokensPropCommitsCommitProp
tejun heotejun heo9355.69%535.71%
jens axboejens axboe5331.74%535.71%
alan d. brunellealan d. brunelle105.99%17.14%
al viroal viro52.99%17.14%
nick pigginnick piggin42.40%17.14%
ma jianpengma jianpeng21.20%17.14%
Total167100.00%14100.00%

/* * Switch this queue to the given IO scheduler. */
static int __elevator_change(struct request_queue *q, const char *name) { char elevator_name[ELV_NAME_MAX]; struct elevator_type *e; if (!q->elevator) return -ENXIO; strlcpy(elevator_name, name, sizeof(elevator_name)); e = elevator_get(strstrip(elevator_name), true); if (!e) { printk(KERN_ERR "elevator: type %s not found\n", elevator_name); return -EINVAL; } if (!strcmp(elevator_name, q->elevator->type->elevator_name)) { elevator_put(e); return 0; } return elevator_switch(q, e); }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe8977.39%436.36%
martin k. petersenmartin k. petersen97.83%19.09%
nate diller*nate diller*86.96%19.09%
tejun heotejun heo32.61%218.18%
kosaki motohirokosaki motohiro32.61%19.09%
tomoki sekiyamatomoki sekiyama21.74%19.09%
li zefanli zefan10.87%19.09%
Total115100.00%11100.00%


int elevator_change(struct request_queue *q, const char *name) { int ret; /* Protect q->elevator from elevator_init() */ mutex_lock(&q->sysfs_lock); ret = __elevator_change(q, name); mutex_unlock(&q->sysfs_lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
tomoki sekiyamatomoki sekiyama47100.00%1100.00%
Total47100.00%1100.00%

EXPORT_SYMBOL(elevator_change);
ssize_t elv_iosched_store(struct request_queue *q, const char *name, size_t count) { int ret; if (!q->elevator) return count; ret = __elevator_change(q, name); if (!ret) return count; printk(KERN_ERR "elevator: switch to %s failed\n", name); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe4881.36%250.00%
al viroal viro1016.95%125.00%
tomoki sekiyamatomoki sekiyama11.69%125.00%
Total59100.00%4100.00%


ssize_t elv_iosched_show(struct request_queue *q, char *name) { struct elevator_queue *e = q->elevator; struct elevator_type *elv; struct elevator_type *__e; int len = 0; if (!q->elevator || !blk_queue_stackable(q)) return sprintf(name, "none\n"); elv = e->type; spin_lock(&elv_list_lock); list_for_each_entry(__e, &elv_list, list) { if (!strcmp(elv->elevator_name, __e->elevator_name)) len += sprintf(name+len, "[%s] ", elv->elevator_name); else len += sprintf(name+len, "%s ", __e->elevator_name); } spin_unlock(&elv_list_lock); len += sprintf(len+name, "\n"); return len; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe10974.66%444.44%
martin k. petersenmartin k. petersen2013.70%111.11%
mike snitzermike snitzer64.11%111.11%
matthias kaehlckematthias kaehlcke64.11%111.11%
vasily tarasovvasily tarasov42.74%111.11%
tejun heotejun heo10.68%111.11%
Total146100.00%9100.00%


struct request *elv_rb_former_request(struct request_queue *q, struct request *rq) { struct rb_node *rbprev = rb_prev(&rq->rb_node); if (rbprev) return rb_entry_rq(rbprev); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe3990.70%266.67%
linus torvaldslinus torvalds49.30%133.33%
Total43100.00%3100.00%

EXPORT_SYMBOL(elv_rb_former_request);
struct request *elv_rb_latter_request(struct request_queue *q, struct request *rq) { struct rb_node *rbnext = rb_next(&rq->rb_node); if (rbnext) return rb_entry_rq(rbnext); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe4195.35%375.00%
martin schwidefskymartin schwidefsky24.65%125.00%
Total43100.00%4100.00%

EXPORT_SYMBOL(elv_rb_latter_request);

Overall Contributors

PersonTokensPropCommitsCommitProp
jens axboejens axboe227351.46%4130.83%
tejun heotejun heo93721.21%2518.80%
al viroal viro3758.49%32.26%
lin minglin ming1423.21%10.75%
linus torvaldslinus torvalds1363.08%53.76%
andrew mortonandrew morton801.81%53.76%
nate diller*nate diller*771.74%32.26%
tomoki sekiyamatomoki sekiyama591.34%21.50%
divyesh shahdivyesh shah481.09%10.75%
martin k. petersenmartin k. petersen330.75%21.50%
alan d. brunellealan d. brunelle310.70%32.26%
mike snitzermike snitzer280.63%32.26%
christoph hellwigchristoph hellwig260.59%10.75%
shaohua lishaohua li260.59%10.75%
thibaut varenethibaut varene160.36%10.75%
greg kroah-hartmangreg kroah-hartman130.29%43.01%
pre-gitpre-git130.29%10.75%
sasha levinsasha levin110.25%10.75%
matthias kaehlckematthias kaehlcke100.23%10.75%
sudip mukherjeesudip mukherjee100.23%10.75%
ma jianpengma jianpeng90.20%10.75%
vasily tarasovvasily tarasov80.18%21.50%
david woodhousedavid woodhouse70.16%10.75%
martin schwidefskymartin schwidefsky60.14%10.75%
ming leiming lei60.14%10.75%
nick pigginnick piggin40.09%10.75%
thomas gleixnerthomas gleixner40.09%10.75%
chao yuchao yu30.07%10.75%
arnaldo carvalho de meloarnaldo carvalho de melo30.07%10.75%
kosaki motohirokosaki motohiro30.07%10.75%
li zefanli zefan30.07%21.50%
jeff moyerjeff moyer20.05%10.75%
kent overstreetkent overstreet20.05%10.75%
patrick mochelpatrick mochel10.02%10.75%
uwe kleine-koeniguwe kleine-koenig10.02%10.75%
wzt wztwzt wzt10.02%10.75%
chuck ebbertchuck ebbert10.02%10.75%
kees cookkees cook10.02%10.75%
adrian bunkadrian bunk10.02%10.75%
emese revfyemese revfy10.02%10.75%
hirofumi ogawahirofumi ogawa10.02%10.75%
harvey harrisonharvey harrison10.02%10.75%
eric sesterhenneric sesterhenn10.02%10.75%
joe perchesjoe perches10.02%10.75%
wang sheng-huiwang sheng-hui10.02%10.75%
rafael j. wysockirafael j. wysocki10.02%10.75%
Total4417100.00%133100.00%
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