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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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1475314530
[ Upstream commit2de791ab49
] Changes from v1: - update commit description with proper ref-accounting justification commitdb37a34c56
("block, bfq: get a ref to a group when adding it to a service tree") introduce leak forbfq_group and blkcg_gq objects because of get/put imbalance. In fact whole idea of original commit is wrong because bfq_group entity can not dissapear under us because it is referenced by child bfq_queue's entities from here: -> bfq_init_entity() ->bfqg_and_blkg_get(bfqg); ->entity->parent = bfqg->my_entity -> bfq_put_queue(bfqq) FINAL_PUT ->bfqg_and_blkg_put(bfqq_group(bfqq)) ->kmem_cache_free(bfq_pool, bfqq); So parent entity can not disappear while child entity is in tree, and child entities already has proper protection. This patch revert commitdb37a34c56
("block, bfq: get a ref to a group when adding it to a service tree") bfq_group leak trace caused by bad commit: -> blkg_alloc -> bfq_pq_alloc -> bfqg_get (+1) ->bfq_activate_bfqq ->bfq_activate_requeue_entity -> __bfq_activate_entity ->bfq_get_entity ->bfqg_and_blkg_get (+1) <==== : Note1 ->bfq_del_bfqq_busy ->bfq_deactivate_entity+0x53/0xc0 [bfq] ->__bfq_deactivate_entity+0x1b8/0x210 [bfq] -> bfq_forget_entity(is_in_service = true) entity->on_st_or_in_serv = false <=== :Note2 if (is_in_service) return; ==> do not touch reference -> blkcg_css_offline -> blkcg_destroy_blkgs -> blkg_destroy -> bfq_pd_offline -> __bfq_deactivate_entity if (!entity->on_st_or_in_serv) /* true, because (Note2) return false; -> bfq_pd_free -> bfqg_put() (-1, byt bfqg->ref == 2) because of (Note2) So bfq_group and blkcg_gq will leak forever, see test-case below. ##TESTCASE_BEGIN: #!/bin/bash max_iters=${1:-100} #prep cgroup mounts mount -t tmpfs cgroup_root /sys/fs/cgroup mkdir /sys/fs/cgroup/blkio mount -t cgroup -o blkio none /sys/fs/cgroup/blkio # Prepare blkdev grep blkio /proc/cgroups truncate -s 1M img losetup /dev/loop0 img echo bfq > /sys/block/loop0/queue/scheduler grep blkio /proc/cgroups for ((i=0;i<max_iters;i++)) do mkdir -p /sys/fs/cgroup/blkio/a echo 0 > /sys/fs/cgroup/blkio/a/cgroup.procs dd if=/dev/loop0 bs=4k count=1 of=/dev/null iflag=direct 2> /dev/null echo 0 > /sys/fs/cgroup/blkio/cgroup.procs rmdir /sys/fs/cgroup/blkio/a grep blkio /proc/cgroups done ##TESTCASE_END: Fixes:db37a34c56
("block, bfq: get a ref to a group when adding it to a service tree") Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
1427 lines
38 KiB
C
1427 lines
38 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* cgroups support for the BFQ I/O scheduler.
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/cgroup.h>
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#include <linux/elevator.h>
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#include <linux/ktime.h>
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#include <linux/rbtree.h>
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#include <linux/ioprio.h>
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#include <linux/sbitmap.h>
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#include <linux/delay.h>
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#include "bfq-iosched.h"
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#ifdef CONFIG_BFQ_CGROUP_DEBUG
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static int bfq_stat_init(struct bfq_stat *stat, gfp_t gfp)
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{
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int ret;
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ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp);
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if (ret)
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return ret;
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atomic64_set(&stat->aux_cnt, 0);
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return 0;
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}
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static void bfq_stat_exit(struct bfq_stat *stat)
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{
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percpu_counter_destroy(&stat->cpu_cnt);
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}
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/**
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* bfq_stat_add - add a value to a bfq_stat
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* @stat: target bfq_stat
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* @val: value to add
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*
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* Add @val to @stat. The caller must ensure that IRQ on the same CPU
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* don't re-enter this function for the same counter.
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*/
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static inline void bfq_stat_add(struct bfq_stat *stat, uint64_t val)
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{
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percpu_counter_add_batch(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH);
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}
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/**
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* bfq_stat_read - read the current value of a bfq_stat
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* @stat: bfq_stat to read
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*/
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static inline uint64_t bfq_stat_read(struct bfq_stat *stat)
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{
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return percpu_counter_sum_positive(&stat->cpu_cnt);
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}
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/**
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* bfq_stat_reset - reset a bfq_stat
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* @stat: bfq_stat to reset
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*/
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static inline void bfq_stat_reset(struct bfq_stat *stat)
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{
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percpu_counter_set(&stat->cpu_cnt, 0);
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atomic64_set(&stat->aux_cnt, 0);
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}
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/**
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* bfq_stat_add_aux - add a bfq_stat into another's aux count
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* @to: the destination bfq_stat
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* @from: the source
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*
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* Add @from's count including the aux one to @to's aux count.
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*/
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static inline void bfq_stat_add_aux(struct bfq_stat *to,
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struct bfq_stat *from)
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{
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atomic64_add(bfq_stat_read(from) + atomic64_read(&from->aux_cnt),
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&to->aux_cnt);
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}
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/**
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* blkg_prfill_stat - prfill callback for bfq_stat
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* @sf: seq_file to print to
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* @pd: policy private data of interest
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* @off: offset to the bfq_stat in @pd
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*
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* prfill callback for printing a bfq_stat.
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*/
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static u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd,
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int off)
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{
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return __blkg_prfill_u64(sf, pd, bfq_stat_read((void *)pd + off));
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}
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/* bfqg stats flags */
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enum bfqg_stats_flags {
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BFQG_stats_waiting = 0,
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BFQG_stats_idling,
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BFQG_stats_empty,
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};
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#define BFQG_FLAG_FNS(name) \
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static void bfqg_stats_mark_##name(struct bfqg_stats *stats) \
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{ \
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stats->flags |= (1 << BFQG_stats_##name); \
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} \
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static void bfqg_stats_clear_##name(struct bfqg_stats *stats) \
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{ \
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stats->flags &= ~(1 << BFQG_stats_##name); \
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} \
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static int bfqg_stats_##name(struct bfqg_stats *stats) \
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{ \
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return (stats->flags & (1 << BFQG_stats_##name)) != 0; \
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} \
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BFQG_FLAG_FNS(waiting)
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BFQG_FLAG_FNS(idling)
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BFQG_FLAG_FNS(empty)
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#undef BFQG_FLAG_FNS
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/* This should be called with the scheduler lock held. */
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static void bfqg_stats_update_group_wait_time(struct bfqg_stats *stats)
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{
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u64 now;
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if (!bfqg_stats_waiting(stats))
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return;
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now = ktime_get_ns();
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if (now > stats->start_group_wait_time)
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bfq_stat_add(&stats->group_wait_time,
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now - stats->start_group_wait_time);
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bfqg_stats_clear_waiting(stats);
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}
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/* This should be called with the scheduler lock held. */
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static void bfqg_stats_set_start_group_wait_time(struct bfq_group *bfqg,
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struct bfq_group *curr_bfqg)
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{
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struct bfqg_stats *stats = &bfqg->stats;
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if (bfqg_stats_waiting(stats))
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return;
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if (bfqg == curr_bfqg)
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return;
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stats->start_group_wait_time = ktime_get_ns();
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bfqg_stats_mark_waiting(stats);
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}
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/* This should be called with the scheduler lock held. */
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static void bfqg_stats_end_empty_time(struct bfqg_stats *stats)
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{
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u64 now;
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if (!bfqg_stats_empty(stats))
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return;
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now = ktime_get_ns();
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if (now > stats->start_empty_time)
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bfq_stat_add(&stats->empty_time,
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now - stats->start_empty_time);
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bfqg_stats_clear_empty(stats);
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}
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void bfqg_stats_update_dequeue(struct bfq_group *bfqg)
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{
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bfq_stat_add(&bfqg->stats.dequeue, 1);
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}
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void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg)
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{
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struct bfqg_stats *stats = &bfqg->stats;
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if (blkg_rwstat_total(&stats->queued))
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return;
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/*
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* group is already marked empty. This can happen if bfqq got new
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* request in parent group and moved to this group while being added
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* to service tree. Just ignore the event and move on.
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*/
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if (bfqg_stats_empty(stats))
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return;
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stats->start_empty_time = ktime_get_ns();
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bfqg_stats_mark_empty(stats);
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}
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void bfqg_stats_update_idle_time(struct bfq_group *bfqg)
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{
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struct bfqg_stats *stats = &bfqg->stats;
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if (bfqg_stats_idling(stats)) {
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u64 now = ktime_get_ns();
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if (now > stats->start_idle_time)
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bfq_stat_add(&stats->idle_time,
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now - stats->start_idle_time);
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bfqg_stats_clear_idling(stats);
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}
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}
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void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg)
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{
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struct bfqg_stats *stats = &bfqg->stats;
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stats->start_idle_time = ktime_get_ns();
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bfqg_stats_mark_idling(stats);
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}
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void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg)
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{
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struct bfqg_stats *stats = &bfqg->stats;
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bfq_stat_add(&stats->avg_queue_size_sum,
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blkg_rwstat_total(&stats->queued));
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bfq_stat_add(&stats->avg_queue_size_samples, 1);
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bfqg_stats_update_group_wait_time(stats);
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}
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void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
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unsigned int op)
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{
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blkg_rwstat_add(&bfqg->stats.queued, op, 1);
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bfqg_stats_end_empty_time(&bfqg->stats);
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if (!(bfqq == ((struct bfq_data *)bfqg->bfqd)->in_service_queue))
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bfqg_stats_set_start_group_wait_time(bfqg, bfqq_group(bfqq));
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}
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void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op)
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{
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blkg_rwstat_add(&bfqg->stats.queued, op, -1);
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}
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void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op)
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{
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blkg_rwstat_add(&bfqg->stats.merged, op, 1);
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}
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void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns,
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u64 io_start_time_ns, unsigned int op)
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{
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struct bfqg_stats *stats = &bfqg->stats;
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u64 now = ktime_get_ns();
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if (now > io_start_time_ns)
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blkg_rwstat_add(&stats->service_time, op,
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now - io_start_time_ns);
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if (io_start_time_ns > start_time_ns)
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blkg_rwstat_add(&stats->wait_time, op,
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io_start_time_ns - start_time_ns);
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}
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#else /* CONFIG_BFQ_CGROUP_DEBUG */
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void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
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unsigned int op) { }
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void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op) { }
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void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op) { }
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void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns,
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u64 io_start_time_ns, unsigned int op) { }
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void bfqg_stats_update_dequeue(struct bfq_group *bfqg) { }
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void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg) { }
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void bfqg_stats_update_idle_time(struct bfq_group *bfqg) { }
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void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) { }
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void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg) { }
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#endif /* CONFIG_BFQ_CGROUP_DEBUG */
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#ifdef CONFIG_BFQ_GROUP_IOSCHED
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/*
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* blk-cgroup policy-related handlers
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* The following functions help in converting between blk-cgroup
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* internal structures and BFQ-specific structures.
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*/
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static struct bfq_group *pd_to_bfqg(struct blkg_policy_data *pd)
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{
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return pd ? container_of(pd, struct bfq_group, pd) : NULL;
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}
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struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg)
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{
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return pd_to_blkg(&bfqg->pd);
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}
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static struct bfq_group *blkg_to_bfqg(struct blkcg_gq *blkg)
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{
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return pd_to_bfqg(blkg_to_pd(blkg, &blkcg_policy_bfq));
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}
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/*
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* bfq_group handlers
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* The following functions help in navigating the bfq_group hierarchy
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* by allowing to find the parent of a bfq_group or the bfq_group
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* associated to a bfq_queue.
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*/
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static struct bfq_group *bfqg_parent(struct bfq_group *bfqg)
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{
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struct blkcg_gq *pblkg = bfqg_to_blkg(bfqg)->parent;
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return pblkg ? blkg_to_bfqg(pblkg) : NULL;
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}
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struct bfq_group *bfqq_group(struct bfq_queue *bfqq)
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{
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struct bfq_entity *group_entity = bfqq->entity.parent;
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return group_entity ? container_of(group_entity, struct bfq_group,
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entity) :
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bfqq->bfqd->root_group;
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}
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/*
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* The following two functions handle get and put of a bfq_group by
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* wrapping the related blk-cgroup hooks.
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*/
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static void bfqg_get(struct bfq_group *bfqg)
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{
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bfqg->ref++;
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}
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static void bfqg_put(struct bfq_group *bfqg)
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{
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bfqg->ref--;
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if (bfqg->ref == 0)
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kfree(bfqg);
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}
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static void bfqg_and_blkg_get(struct bfq_group *bfqg)
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{
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/* see comments in bfq_bic_update_cgroup for why refcounting bfqg */
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bfqg_get(bfqg);
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blkg_get(bfqg_to_blkg(bfqg));
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}
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void bfqg_and_blkg_put(struct bfq_group *bfqg)
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{
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blkg_put(bfqg_to_blkg(bfqg));
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bfqg_put(bfqg);
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}
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/* @stats = 0 */
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static void bfqg_stats_reset(struct bfqg_stats *stats)
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{
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#ifdef CONFIG_BFQ_CGROUP_DEBUG
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/* queued stats shouldn't be cleared */
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blkg_rwstat_reset(&stats->merged);
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blkg_rwstat_reset(&stats->service_time);
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blkg_rwstat_reset(&stats->wait_time);
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bfq_stat_reset(&stats->time);
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bfq_stat_reset(&stats->avg_queue_size_sum);
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bfq_stat_reset(&stats->avg_queue_size_samples);
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bfq_stat_reset(&stats->dequeue);
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bfq_stat_reset(&stats->group_wait_time);
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bfq_stat_reset(&stats->idle_time);
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bfq_stat_reset(&stats->empty_time);
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#endif
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}
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/* @to += @from */
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static void bfqg_stats_add_aux(struct bfqg_stats *to, struct bfqg_stats *from)
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{
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if (!to || !from)
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return;
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#ifdef CONFIG_BFQ_CGROUP_DEBUG
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/* queued stats shouldn't be cleared */
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blkg_rwstat_add_aux(&to->merged, &from->merged);
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blkg_rwstat_add_aux(&to->service_time, &from->service_time);
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blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
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bfq_stat_add_aux(&from->time, &from->time);
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bfq_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
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bfq_stat_add_aux(&to->avg_queue_size_samples,
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&from->avg_queue_size_samples);
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bfq_stat_add_aux(&to->dequeue, &from->dequeue);
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bfq_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
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bfq_stat_add_aux(&to->idle_time, &from->idle_time);
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bfq_stat_add_aux(&to->empty_time, &from->empty_time);
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#endif
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}
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/*
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* Transfer @bfqg's stats to its parent's aux counts so that the ancestors'
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* recursive stats can still account for the amount used by this bfqg after
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* it's gone.
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*/
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static void bfqg_stats_xfer_dead(struct bfq_group *bfqg)
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{
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struct bfq_group *parent;
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if (!bfqg) /* root_group */
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return;
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parent = bfqg_parent(bfqg);
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lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock);
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if (unlikely(!parent))
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return;
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bfqg_stats_add_aux(&parent->stats, &bfqg->stats);
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bfqg_stats_reset(&bfqg->stats);
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}
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|
|
void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
|
|
{
|
|
struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
|
|
|
|
entity->weight = entity->new_weight;
|
|
entity->orig_weight = entity->new_weight;
|
|
if (bfqq) {
|
|
bfqq->ioprio = bfqq->new_ioprio;
|
|
bfqq->ioprio_class = bfqq->new_ioprio_class;
|
|
/*
|
|
* Make sure that bfqg and its associated blkg do not
|
|
* disappear before entity.
|
|
*/
|
|
bfqg_and_blkg_get(bfqg);
|
|
}
|
|
entity->parent = bfqg->my_entity; /* NULL for root group */
|
|
entity->sched_data = &bfqg->sched_data;
|
|
}
|
|
|
|
static void bfqg_stats_exit(struct bfqg_stats *stats)
|
|
{
|
|
#ifdef CONFIG_BFQ_CGROUP_DEBUG
|
|
blkg_rwstat_exit(&stats->merged);
|
|
blkg_rwstat_exit(&stats->service_time);
|
|
blkg_rwstat_exit(&stats->wait_time);
|
|
blkg_rwstat_exit(&stats->queued);
|
|
bfq_stat_exit(&stats->time);
|
|
bfq_stat_exit(&stats->avg_queue_size_sum);
|
|
bfq_stat_exit(&stats->avg_queue_size_samples);
|
|
bfq_stat_exit(&stats->dequeue);
|
|
bfq_stat_exit(&stats->group_wait_time);
|
|
bfq_stat_exit(&stats->idle_time);
|
|
bfq_stat_exit(&stats->empty_time);
|
|
#endif
|
|
}
|
|
|
|
static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp)
|
|
{
|
|
#ifdef CONFIG_BFQ_CGROUP_DEBUG
|
|
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) ||
|
|
bfq_stat_init(&stats->time, gfp) ||
|
|
bfq_stat_init(&stats->avg_queue_size_sum, gfp) ||
|
|
bfq_stat_init(&stats->avg_queue_size_samples, gfp) ||
|
|
bfq_stat_init(&stats->dequeue, gfp) ||
|
|
bfq_stat_init(&stats->group_wait_time, gfp) ||
|
|
bfq_stat_init(&stats->idle_time, gfp) ||
|
|
bfq_stat_init(&stats->empty_time, gfp)) {
|
|
bfqg_stats_exit(stats);
|
|
return -ENOMEM;
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct bfq_group_data *cpd_to_bfqgd(struct blkcg_policy_data *cpd)
|
|
{
|
|
return cpd ? container_of(cpd, struct bfq_group_data, pd) : NULL;
|
|
}
|
|
|
|
static struct bfq_group_data *blkcg_to_bfqgd(struct blkcg *blkcg)
|
|
{
|
|
return cpd_to_bfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_bfq));
|
|
}
|
|
|
|
static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
|
|
{
|
|
struct bfq_group_data *bgd;
|
|
|
|
bgd = kzalloc(sizeof(*bgd), gfp);
|
|
if (!bgd)
|
|
return NULL;
|
|
return &bgd->pd;
|
|
}
|
|
|
|
static void bfq_cpd_init(struct blkcg_policy_data *cpd)
|
|
{
|
|
struct bfq_group_data *d = cpd_to_bfqgd(cpd);
|
|
|
|
d->weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ?
|
|
CGROUP_WEIGHT_DFL : BFQ_WEIGHT_LEGACY_DFL;
|
|
}
|
|
|
|
static void bfq_cpd_free(struct blkcg_policy_data *cpd)
|
|
{
|
|
kfree(cpd_to_bfqgd(cpd));
|
|
}
|
|
|
|
static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, struct request_queue *q,
|
|
struct blkcg *blkcg)
|
|
{
|
|
struct bfq_group *bfqg;
|
|
|
|
bfqg = kzalloc_node(sizeof(*bfqg), gfp, q->node);
|
|
if (!bfqg)
|
|
return NULL;
|
|
|
|
if (bfqg_stats_init(&bfqg->stats, gfp)) {
|
|
kfree(bfqg);
|
|
return NULL;
|
|
}
|
|
|
|
/* see comments in bfq_bic_update_cgroup for why refcounting */
|
|
bfqg_get(bfqg);
|
|
return &bfqg->pd;
|
|
}
|
|
|
|
static void bfq_pd_init(struct blkg_policy_data *pd)
|
|
{
|
|
struct blkcg_gq *blkg = pd_to_blkg(pd);
|
|
struct bfq_group *bfqg = blkg_to_bfqg(blkg);
|
|
struct bfq_data *bfqd = blkg->q->elevator->elevator_data;
|
|
struct bfq_entity *entity = &bfqg->entity;
|
|
struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg);
|
|
|
|
entity->orig_weight = entity->weight = entity->new_weight = d->weight;
|
|
entity->my_sched_data = &bfqg->sched_data;
|
|
bfqg->my_entity = entity; /*
|
|
* the root_group's will be set to NULL
|
|
* in bfq_init_queue()
|
|
*/
|
|
bfqg->bfqd = bfqd;
|
|
bfqg->active_entities = 0;
|
|
bfqg->rq_pos_tree = RB_ROOT;
|
|
}
|
|
|
|
static void bfq_pd_free(struct blkg_policy_data *pd)
|
|
{
|
|
struct bfq_group *bfqg = pd_to_bfqg(pd);
|
|
|
|
bfqg_stats_exit(&bfqg->stats);
|
|
bfqg_put(bfqg);
|
|
}
|
|
|
|
static void bfq_pd_reset_stats(struct blkg_policy_data *pd)
|
|
{
|
|
struct bfq_group *bfqg = pd_to_bfqg(pd);
|
|
|
|
bfqg_stats_reset(&bfqg->stats);
|
|
}
|
|
|
|
static void bfq_group_set_parent(struct bfq_group *bfqg,
|
|
struct bfq_group *parent)
|
|
{
|
|
struct bfq_entity *entity;
|
|
|
|
entity = &bfqg->entity;
|
|
entity->parent = parent->my_entity;
|
|
entity->sched_data = &parent->sched_data;
|
|
}
|
|
|
|
static struct bfq_group *bfq_lookup_bfqg(struct bfq_data *bfqd,
|
|
struct blkcg *blkcg)
|
|
{
|
|
struct blkcg_gq *blkg;
|
|
|
|
blkg = blkg_lookup(blkcg, bfqd->queue);
|
|
if (likely(blkg))
|
|
return blkg_to_bfqg(blkg);
|
|
return NULL;
|
|
}
|
|
|
|
struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd,
|
|
struct blkcg *blkcg)
|
|
{
|
|
struct bfq_group *bfqg, *parent;
|
|
struct bfq_entity *entity;
|
|
|
|
bfqg = bfq_lookup_bfqg(bfqd, blkcg);
|
|
|
|
if (unlikely(!bfqg))
|
|
return NULL;
|
|
|
|
/*
|
|
* Update chain of bfq_groups as we might be handling a leaf group
|
|
* which, along with some of its relatives, has not been hooked yet
|
|
* to the private hierarchy of BFQ.
|
|
*/
|
|
entity = &bfqg->entity;
|
|
for_each_entity(entity) {
|
|
struct bfq_group *curr_bfqg = container_of(entity,
|
|
struct bfq_group, entity);
|
|
if (curr_bfqg != bfqd->root_group) {
|
|
parent = bfqg_parent(curr_bfqg);
|
|
if (!parent)
|
|
parent = bfqd->root_group;
|
|
bfq_group_set_parent(curr_bfqg, parent);
|
|
}
|
|
}
|
|
|
|
return bfqg;
|
|
}
|
|
|
|
/**
|
|
* bfq_bfqq_move - migrate @bfqq to @bfqg.
|
|
* @bfqd: queue descriptor.
|
|
* @bfqq: the queue to move.
|
|
* @bfqg: the group to move to.
|
|
*
|
|
* Move @bfqq to @bfqg, deactivating it from its old group and reactivating
|
|
* it on the new one. Avoid putting the entity on the old group idle tree.
|
|
*
|
|
* Must be called under the scheduler lock, to make sure that the blkg
|
|
* owning @bfqg does not disappear (see comments in
|
|
* bfq_bic_update_cgroup on guaranteeing the consistency of blkg
|
|
* objects).
|
|
*/
|
|
void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
|
|
struct bfq_group *bfqg)
|
|
{
|
|
struct bfq_entity *entity = &bfqq->entity;
|
|
|
|
/*
|
|
* Get extra reference to prevent bfqq from being freed in
|
|
* next possible expire or deactivate.
|
|
*/
|
|
bfqq->ref++;
|
|
|
|
/* If bfqq is empty, then bfq_bfqq_expire also invokes
|
|
* bfq_del_bfqq_busy, thereby removing bfqq and its entity
|
|
* from data structures related to current group. Otherwise we
|
|
* need to remove bfqq explicitly with bfq_deactivate_bfqq, as
|
|
* we do below.
|
|
*/
|
|
if (bfqq == bfqd->in_service_queue)
|
|
bfq_bfqq_expire(bfqd, bfqd->in_service_queue,
|
|
false, BFQQE_PREEMPTED);
|
|
|
|
if (bfq_bfqq_busy(bfqq))
|
|
bfq_deactivate_bfqq(bfqd, bfqq, false, false);
|
|
else if (entity->on_st)
|
|
bfq_put_idle_entity(bfq_entity_service_tree(entity), entity);
|
|
bfqg_and_blkg_put(bfqq_group(bfqq));
|
|
|
|
entity->parent = bfqg->my_entity;
|
|
entity->sched_data = &bfqg->sched_data;
|
|
/* pin down bfqg and its associated blkg */
|
|
bfqg_and_blkg_get(bfqg);
|
|
|
|
if (bfq_bfqq_busy(bfqq)) {
|
|
if (unlikely(!bfqd->nonrot_with_queueing))
|
|
bfq_pos_tree_add_move(bfqd, bfqq);
|
|
bfq_activate_bfqq(bfqd, bfqq);
|
|
}
|
|
|
|
if (!bfqd->in_service_queue && !bfqd->rq_in_driver)
|
|
bfq_schedule_dispatch(bfqd);
|
|
/* release extra ref taken above, bfqq may happen to be freed now */
|
|
bfq_put_queue(bfqq);
|
|
}
|
|
|
|
/**
|
|
* __bfq_bic_change_cgroup - move @bic to @cgroup.
|
|
* @bfqd: the queue descriptor.
|
|
* @bic: the bic to move.
|
|
* @blkcg: the blk-cgroup to move to.
|
|
*
|
|
* Move bic to blkcg, assuming that bfqd->lock is held; which makes
|
|
* sure that the reference to cgroup is valid across the call (see
|
|
* comments in bfq_bic_update_cgroup on this issue)
|
|
*
|
|
* NOTE: an alternative approach might have been to store the current
|
|
* cgroup in bfqq and getting a reference to it, reducing the lookup
|
|
* time here, at the price of slightly more complex code.
|
|
*/
|
|
static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
|
|
struct bfq_io_cq *bic,
|
|
struct blkcg *blkcg)
|
|
{
|
|
struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0);
|
|
struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1);
|
|
struct bfq_group *bfqg;
|
|
struct bfq_entity *entity;
|
|
|
|
bfqg = bfq_find_set_group(bfqd, blkcg);
|
|
|
|
if (unlikely(!bfqg))
|
|
bfqg = bfqd->root_group;
|
|
|
|
if (async_bfqq) {
|
|
entity = &async_bfqq->entity;
|
|
|
|
if (entity->sched_data != &bfqg->sched_data) {
|
|
bic_set_bfqq(bic, NULL, 0);
|
|
bfq_release_process_ref(bfqd, async_bfqq);
|
|
}
|
|
}
|
|
|
|
if (sync_bfqq) {
|
|
entity = &sync_bfqq->entity;
|
|
if (entity->sched_data != &bfqg->sched_data)
|
|
bfq_bfqq_move(bfqd, sync_bfqq, bfqg);
|
|
}
|
|
|
|
return bfqg;
|
|
}
|
|
|
|
void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio)
|
|
{
|
|
struct bfq_data *bfqd = bic_to_bfqd(bic);
|
|
struct bfq_group *bfqg = NULL;
|
|
uint64_t serial_nr;
|
|
|
|
rcu_read_lock();
|
|
serial_nr = __bio_blkcg(bio)->css.serial_nr;
|
|
|
|
/*
|
|
* Check whether blkcg has changed. The condition may trigger
|
|
* spuriously on a newly created cic but there's no harm.
|
|
*/
|
|
if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr))
|
|
goto out;
|
|
|
|
bfqg = __bfq_bic_change_cgroup(bfqd, bic, __bio_blkcg(bio));
|
|
/*
|
|
* Update blkg_path for bfq_log_* functions. We cache this
|
|
* path, and update it here, for the following
|
|
* reasons. Operations on blkg objects in blk-cgroup are
|
|
* protected with the request_queue lock, and not with the
|
|
* lock that protects the instances of this scheduler
|
|
* (bfqd->lock). This exposes BFQ to the following sort of
|
|
* race.
|
|
*
|
|
* The blkg_lookup performed in bfq_get_queue, protected
|
|
* through rcu, may happen to return the address of a copy of
|
|
* the original blkg. If this is the case, then the
|
|
* bfqg_and_blkg_get performed in bfq_get_queue, to pin down
|
|
* the blkg, is useless: it does not prevent blk-cgroup code
|
|
* from destroying both the original blkg and all objects
|
|
* directly or indirectly referred by the copy of the
|
|
* blkg.
|
|
*
|
|
* On the bright side, destroy operations on a blkg invoke, as
|
|
* a first step, hooks of the scheduler associated with the
|
|
* blkg. And these hooks are executed with bfqd->lock held for
|
|
* BFQ. As a consequence, for any blkg associated with the
|
|
* request queue this instance of the scheduler is attached
|
|
* to, we are guaranteed that such a blkg is not destroyed, and
|
|
* that all the pointers it contains are consistent, while we
|
|
* are holding bfqd->lock. A blkg_lookup performed with
|
|
* bfqd->lock held then returns a fully consistent blkg, which
|
|
* remains consistent until this lock is held.
|
|
*
|
|
* Thanks to the last fact, and to the fact that: (1) bfqg has
|
|
* been obtained through a blkg_lookup in the above
|
|
* assignment, and (2) bfqd->lock is being held, here we can
|
|
* safely use the policy data for the involved blkg (i.e., the
|
|
* field bfqg->pd) to get to the blkg associated with bfqg,
|
|
* and then we can safely use any field of blkg. After we
|
|
* release bfqd->lock, even just getting blkg through this
|
|
* bfqg may cause dangling references to be traversed, as
|
|
* bfqg->pd may not exist any more.
|
|
*
|
|
* In view of the above facts, here we cache, in the bfqg, any
|
|
* blkg data we may need for this bic, and for its associated
|
|
* bfq_queue. As of now, we need to cache only the path of the
|
|
* blkg, which is used in the bfq_log_* functions.
|
|
*
|
|
* Finally, note that bfqg itself needs to be protected from
|
|
* destruction on the blkg_free of the original blkg (which
|
|
* invokes bfq_pd_free). We use an additional private
|
|
* refcounter for bfqg, to let it disappear only after no
|
|
* bfq_queue refers to it any longer.
|
|
*/
|
|
blkg_path(bfqg_to_blkg(bfqg), bfqg->blkg_path, sizeof(bfqg->blkg_path));
|
|
bic->blkcg_serial_nr = serial_nr;
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* bfq_flush_idle_tree - deactivate any entity on the idle tree of @st.
|
|
* @st: the service tree being flushed.
|
|
*/
|
|
static void bfq_flush_idle_tree(struct bfq_service_tree *st)
|
|
{
|
|
struct bfq_entity *entity = st->first_idle;
|
|
|
|
for (; entity ; entity = st->first_idle)
|
|
__bfq_deactivate_entity(entity, false);
|
|
}
|
|
|
|
/**
|
|
* bfq_reparent_leaf_entity - move leaf entity to the root_group.
|
|
* @bfqd: the device data structure with the root group.
|
|
* @entity: the entity to move, if entity is a leaf; or the parent entity
|
|
* of an active leaf entity to move, if entity is not a leaf.
|
|
*/
|
|
static void bfq_reparent_leaf_entity(struct bfq_data *bfqd,
|
|
struct bfq_entity *entity,
|
|
int ioprio_class)
|
|
{
|
|
struct bfq_queue *bfqq;
|
|
struct bfq_entity *child_entity = entity;
|
|
|
|
while (child_entity->my_sched_data) { /* leaf not reached yet */
|
|
struct bfq_sched_data *child_sd = child_entity->my_sched_data;
|
|
struct bfq_service_tree *child_st = child_sd->service_tree +
|
|
ioprio_class;
|
|
struct rb_root *child_active = &child_st->active;
|
|
|
|
child_entity = bfq_entity_of(rb_first(child_active));
|
|
|
|
if (!child_entity)
|
|
child_entity = child_sd->in_service_entity;
|
|
}
|
|
|
|
bfqq = bfq_entity_to_bfqq(child_entity);
|
|
bfq_bfqq_move(bfqd, bfqq, bfqd->root_group);
|
|
}
|
|
|
|
/**
|
|
* bfq_reparent_active_queues - move to the root group all active queues.
|
|
* @bfqd: the device data structure with the root group.
|
|
* @bfqg: the group to move from.
|
|
* @st: the service tree to start the search from.
|
|
*/
|
|
static void bfq_reparent_active_queues(struct bfq_data *bfqd,
|
|
struct bfq_group *bfqg,
|
|
struct bfq_service_tree *st,
|
|
int ioprio_class)
|
|
{
|
|
struct rb_root *active = &st->active;
|
|
struct bfq_entity *entity;
|
|
|
|
while ((entity = bfq_entity_of(rb_first(active))))
|
|
bfq_reparent_leaf_entity(bfqd, entity, ioprio_class);
|
|
|
|
if (bfqg->sched_data.in_service_entity)
|
|
bfq_reparent_leaf_entity(bfqd,
|
|
bfqg->sched_data.in_service_entity,
|
|
ioprio_class);
|
|
}
|
|
|
|
/**
|
|
* bfq_pd_offline - deactivate the entity associated with @pd,
|
|
* and reparent its children entities.
|
|
* @pd: descriptor of the policy going offline.
|
|
*
|
|
* blkio already grabs the queue_lock for us, so no need to use
|
|
* RCU-based magic
|
|
*/
|
|
static void bfq_pd_offline(struct blkg_policy_data *pd)
|
|
{
|
|
struct bfq_service_tree *st;
|
|
struct bfq_group *bfqg = pd_to_bfqg(pd);
|
|
struct bfq_data *bfqd = bfqg->bfqd;
|
|
struct bfq_entity *entity = bfqg->my_entity;
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
spin_lock_irqsave(&bfqd->lock, flags);
|
|
|
|
if (!entity) /* root group */
|
|
goto put_async_queues;
|
|
|
|
/*
|
|
* Empty all service_trees belonging to this group before
|
|
* deactivating the group itself.
|
|
*/
|
|
for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) {
|
|
st = bfqg->sched_data.service_tree + i;
|
|
|
|
/*
|
|
* It may happen that some queues are still active
|
|
* (busy) upon group destruction (if the corresponding
|
|
* processes have been forced to terminate). We move
|
|
* all the leaf entities corresponding to these queues
|
|
* to the root_group.
|
|
* Also, it may happen that the group has an entity
|
|
* in service, which is disconnected from the active
|
|
* tree: it must be moved, too.
|
|
* There is no need to put the sync queues, as the
|
|
* scheduler has taken no reference.
|
|
*/
|
|
bfq_reparent_active_queues(bfqd, bfqg, st, i);
|
|
|
|
/*
|
|
* The idle tree may still contain bfq_queues
|
|
* belonging to exited task because they never
|
|
* migrated to a different cgroup from the one being
|
|
* destroyed now. In addition, even
|
|
* bfq_reparent_active_queues() may happen to add some
|
|
* entities to the idle tree. It happens if, in some
|
|
* of the calls to bfq_bfqq_move() performed by
|
|
* bfq_reparent_active_queues(), the queue to move is
|
|
* empty and gets expired.
|
|
*/
|
|
bfq_flush_idle_tree(st);
|
|
}
|
|
|
|
__bfq_deactivate_entity(entity, false);
|
|
|
|
put_async_queues:
|
|
bfq_put_async_queues(bfqd, bfqg);
|
|
|
|
spin_unlock_irqrestore(&bfqd->lock, flags);
|
|
/*
|
|
* @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...
|
|
*/
|
|
bfqg_stats_xfer_dead(bfqg);
|
|
}
|
|
|
|
void bfq_end_wr_async(struct bfq_data *bfqd)
|
|
{
|
|
struct blkcg_gq *blkg;
|
|
|
|
list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) {
|
|
struct bfq_group *bfqg = blkg_to_bfqg(blkg);
|
|
|
|
bfq_end_wr_async_queues(bfqd, bfqg);
|
|
}
|
|
bfq_end_wr_async_queues(bfqd, bfqd->root_group);
|
|
}
|
|
|
|
static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v)
|
|
{
|
|
struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
|
|
struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
|
|
unsigned int val = 0;
|
|
|
|
if (bfqgd)
|
|
val = bfqgd->weight;
|
|
|
|
seq_printf(sf, "%u\n", val);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 bfqg_prfill_weight_device(struct seq_file *sf,
|
|
struct blkg_policy_data *pd, int off)
|
|
{
|
|
struct bfq_group *bfqg = pd_to_bfqg(pd);
|
|
|
|
if (!bfqg->entity.dev_weight)
|
|
return 0;
|
|
return __blkg_prfill_u64(sf, pd, bfqg->entity.dev_weight);
|
|
}
|
|
|
|
static int bfq_io_show_weight(struct seq_file *sf, void *v)
|
|
{
|
|
struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
|
|
struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
|
|
|
|
seq_printf(sf, "default %u\n", bfqgd->weight);
|
|
blkcg_print_blkgs(sf, blkcg, bfqg_prfill_weight_device,
|
|
&blkcg_policy_bfq, 0, false);
|
|
return 0;
|
|
}
|
|
|
|
static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight)
|
|
{
|
|
weight = dev_weight ?: weight;
|
|
|
|
bfqg->entity.dev_weight = dev_weight;
|
|
/*
|
|
* Setting the prio_changed flag of the entity
|
|
* to 1 with new_weight == weight would re-set
|
|
* the value of the weight to its ioprio mapping.
|
|
* Set the flag only if necessary.
|
|
*/
|
|
if ((unsigned short)weight != bfqg->entity.new_weight) {
|
|
bfqg->entity.new_weight = (unsigned short)weight;
|
|
/*
|
|
* Make sure that the above new value has been
|
|
* stored in bfqg->entity.new_weight before
|
|
* setting the prio_changed flag. In fact,
|
|
* this flag may be read asynchronously (in
|
|
* critical sections protected by a different
|
|
* lock than that held here), and finding this
|
|
* flag set may cause the execution of the code
|
|
* for updating parameters whose value may
|
|
* depend also on bfqg->entity.new_weight (in
|
|
* __bfq_entity_update_weight_prio).
|
|
* This barrier makes sure that the new value
|
|
* of bfqg->entity.new_weight is correctly
|
|
* seen in that code.
|
|
*/
|
|
smp_wmb();
|
|
bfqg->entity.prio_changed = 1;
|
|
}
|
|
}
|
|
|
|
static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css,
|
|
struct cftype *cftype,
|
|
u64 val)
|
|
{
|
|
struct blkcg *blkcg = css_to_blkcg(css);
|
|
struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
|
|
struct blkcg_gq *blkg;
|
|
int ret = -ERANGE;
|
|
|
|
if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT)
|
|
return ret;
|
|
|
|
ret = 0;
|
|
spin_lock_irq(&blkcg->lock);
|
|
bfqgd->weight = (unsigned short)val;
|
|
hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
|
|
struct bfq_group *bfqg = blkg_to_bfqg(blkg);
|
|
|
|
if (bfqg)
|
|
bfq_group_set_weight(bfqg, val, 0);
|
|
}
|
|
spin_unlock_irq(&blkcg->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes,
|
|
loff_t off)
|
|
{
|
|
int ret;
|
|
struct blkg_conf_ctx ctx;
|
|
struct blkcg *blkcg = css_to_blkcg(of_css(of));
|
|
struct bfq_group *bfqg;
|
|
u64 v;
|
|
|
|
ret = blkg_conf_prep(blkcg, &blkcg_policy_bfq, buf, &ctx);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (sscanf(ctx.body, "%llu", &v) == 1) {
|
|
/* require "default" on dfl */
|
|
ret = -ERANGE;
|
|
if (!v)
|
|
goto out;
|
|
} else if (!strcmp(strim(ctx.body), "default")) {
|
|
v = 0;
|
|
} else {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
bfqg = blkg_to_bfqg(ctx.blkg);
|
|
|
|
ret = -ERANGE;
|
|
if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) {
|
|
bfq_group_set_weight(bfqg, bfqg->entity.weight, v);
|
|
ret = 0;
|
|
}
|
|
out:
|
|
blkg_conf_finish(&ctx);
|
|
return ret ?: nbytes;
|
|
}
|
|
|
|
static ssize_t bfq_io_set_weight(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 = bfq_io_set_weight_legacy(of_css(of), NULL, v);
|
|
return ret ?: nbytes;
|
|
}
|
|
|
|
return bfq_io_set_device_weight(of, buf, nbytes, off);
|
|
}
|
|
|
|
#ifdef CONFIG_BFQ_CGROUP_DEBUG
|
|
static int bfqg_print_stat(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
|
|
&blkcg_policy_bfq, seq_cft(sf)->private, false);
|
|
return 0;
|
|
}
|
|
|
|
static int bfqg_print_rwstat(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat,
|
|
&blkcg_policy_bfq, seq_cft(sf)->private, true);
|
|
return 0;
|
|
}
|
|
|
|
static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
|
|
struct blkg_policy_data *pd, int off)
|
|
{
|
|
struct blkcg_gq *blkg = pd_to_blkg(pd);
|
|
struct blkcg_gq *pos_blkg;
|
|
struct cgroup_subsys_state *pos_css;
|
|
u64 sum = 0;
|
|
|
|
lockdep_assert_held(&blkg->q->queue_lock);
|
|
|
|
rcu_read_lock();
|
|
blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
|
|
struct bfq_stat *stat;
|
|
|
|
if (!pos_blkg->online)
|
|
continue;
|
|
|
|
stat = (void *)blkg_to_pd(pos_blkg, &blkcg_policy_bfq) + off;
|
|
sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return __blkg_prfill_u64(sf, pd, sum);
|
|
}
|
|
|
|
static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf,
|
|
struct blkg_policy_data *pd, int off)
|
|
{
|
|
struct blkg_rwstat_sample sum;
|
|
|
|
blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum);
|
|
return __blkg_prfill_rwstat(sf, pd, &sum);
|
|
}
|
|
|
|
static int bfqg_print_stat_recursive(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
|
|
bfqg_prfill_stat_recursive, &blkcg_policy_bfq,
|
|
seq_cft(sf)->private, false);
|
|
return 0;
|
|
}
|
|
|
|
static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
|
|
bfqg_prfill_rwstat_recursive, &blkcg_policy_bfq,
|
|
seq_cft(sf)->private, true);
|
|
return 0;
|
|
}
|
|
|
|
static u64 bfqg_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 bfqg_print_stat_sectors(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
|
|
bfqg_prfill_sectors, &blkcg_policy_bfq, 0, false);
|
|
return 0;
|
|
}
|
|
|
|
static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf,
|
|
struct blkg_policy_data *pd, int off)
|
|
{
|
|
struct blkg_rwstat_sample tmp;
|
|
|
|
blkg_rwstat_recursive_sum(pd->blkg, NULL,
|
|
offsetof(struct blkcg_gq, stat_bytes), &tmp);
|
|
|
|
return __blkg_prfill_u64(sf, pd,
|
|
(tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9);
|
|
}
|
|
|
|
static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
|
|
bfqg_prfill_sectors_recursive, &blkcg_policy_bfq, 0,
|
|
false);
|
|
return 0;
|
|
}
|
|
|
|
static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf,
|
|
struct blkg_policy_data *pd, int off)
|
|
{
|
|
struct bfq_group *bfqg = pd_to_bfqg(pd);
|
|
u64 samples = bfq_stat_read(&bfqg->stats.avg_queue_size_samples);
|
|
u64 v = 0;
|
|
|
|
if (samples) {
|
|
v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum);
|
|
v = div64_u64(v, samples);
|
|
}
|
|
__blkg_prfill_u64(sf, pd, v);
|
|
return 0;
|
|
}
|
|
|
|
/* print avg_queue_size */
|
|
static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v)
|
|
{
|
|
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
|
|
bfqg_prfill_avg_queue_size, &blkcg_policy_bfq,
|
|
0, false);
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_BFQ_CGROUP_DEBUG */
|
|
|
|
struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
|
|
{
|
|
int ret;
|
|
|
|
ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq);
|
|
if (ret)
|
|
return NULL;
|
|
|
|
return blkg_to_bfqg(bfqd->queue->root_blkg);
|
|
}
|
|
|
|
struct blkcg_policy blkcg_policy_bfq = {
|
|
.dfl_cftypes = bfq_blkg_files,
|
|
.legacy_cftypes = bfq_blkcg_legacy_files,
|
|
|
|
.cpd_alloc_fn = bfq_cpd_alloc,
|
|
.cpd_init_fn = bfq_cpd_init,
|
|
.cpd_bind_fn = bfq_cpd_init,
|
|
.cpd_free_fn = bfq_cpd_free,
|
|
|
|
.pd_alloc_fn = bfq_pd_alloc,
|
|
.pd_init_fn = bfq_pd_init,
|
|
.pd_offline_fn = bfq_pd_offline,
|
|
.pd_free_fn = bfq_pd_free,
|
|
.pd_reset_stats_fn = bfq_pd_reset_stats,
|
|
};
|
|
|
|
struct cftype bfq_blkcg_legacy_files[] = {
|
|
{
|
|
.name = "bfq.weight",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = bfq_io_show_weight_legacy,
|
|
.write_u64 = bfq_io_set_weight_legacy,
|
|
},
|
|
{
|
|
.name = "bfq.weight_device",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = bfq_io_show_weight,
|
|
.write = bfq_io_set_weight,
|
|
},
|
|
|
|
/* statistics, covers only the tasks in the bfqg */
|
|
{
|
|
.name = "bfq.io_service_bytes",
|
|
.private = (unsigned long)&blkcg_policy_bfq,
|
|
.seq_show = blkg_print_stat_bytes,
|
|
},
|
|
{
|
|
.name = "bfq.io_serviced",
|
|
.private = (unsigned long)&blkcg_policy_bfq,
|
|
.seq_show = blkg_print_stat_ios,
|
|
},
|
|
#ifdef CONFIG_BFQ_CGROUP_DEBUG
|
|
{
|
|
.name = "bfq.time",
|
|
.private = offsetof(struct bfq_group, stats.time),
|
|
.seq_show = bfqg_print_stat,
|
|
},
|
|
{
|
|
.name = "bfq.sectors",
|
|
.seq_show = bfqg_print_stat_sectors,
|
|
},
|
|
{
|
|
.name = "bfq.io_service_time",
|
|
.private = offsetof(struct bfq_group, stats.service_time),
|
|
.seq_show = bfqg_print_rwstat,
|
|
},
|
|
{
|
|
.name = "bfq.io_wait_time",
|
|
.private = offsetof(struct bfq_group, stats.wait_time),
|
|
.seq_show = bfqg_print_rwstat,
|
|
},
|
|
{
|
|
.name = "bfq.io_merged",
|
|
.private = offsetof(struct bfq_group, stats.merged),
|
|
.seq_show = bfqg_print_rwstat,
|
|
},
|
|
{
|
|
.name = "bfq.io_queued",
|
|
.private = offsetof(struct bfq_group, stats.queued),
|
|
.seq_show = bfqg_print_rwstat,
|
|
},
|
|
#endif /* CONFIG_BFQ_CGROUP_DEBUG */
|
|
|
|
/* the same statistics which cover the bfqg and its descendants */
|
|
{
|
|
.name = "bfq.io_service_bytes_recursive",
|
|
.private = (unsigned long)&blkcg_policy_bfq,
|
|
.seq_show = blkg_print_stat_bytes_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.io_serviced_recursive",
|
|
.private = (unsigned long)&blkcg_policy_bfq,
|
|
.seq_show = blkg_print_stat_ios_recursive,
|
|
},
|
|
#ifdef CONFIG_BFQ_CGROUP_DEBUG
|
|
{
|
|
.name = "bfq.time_recursive",
|
|
.private = offsetof(struct bfq_group, stats.time),
|
|
.seq_show = bfqg_print_stat_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.sectors_recursive",
|
|
.seq_show = bfqg_print_stat_sectors_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.io_service_time_recursive",
|
|
.private = offsetof(struct bfq_group, stats.service_time),
|
|
.seq_show = bfqg_print_rwstat_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.io_wait_time_recursive",
|
|
.private = offsetof(struct bfq_group, stats.wait_time),
|
|
.seq_show = bfqg_print_rwstat_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.io_merged_recursive",
|
|
.private = offsetof(struct bfq_group, stats.merged),
|
|
.seq_show = bfqg_print_rwstat_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.io_queued_recursive",
|
|
.private = offsetof(struct bfq_group, stats.queued),
|
|
.seq_show = bfqg_print_rwstat_recursive,
|
|
},
|
|
{
|
|
.name = "bfq.avg_queue_size",
|
|
.seq_show = bfqg_print_avg_queue_size,
|
|
},
|
|
{
|
|
.name = "bfq.group_wait_time",
|
|
.private = offsetof(struct bfq_group, stats.group_wait_time),
|
|
.seq_show = bfqg_print_stat,
|
|
},
|
|
{
|
|
.name = "bfq.idle_time",
|
|
.private = offsetof(struct bfq_group, stats.idle_time),
|
|
.seq_show = bfqg_print_stat,
|
|
},
|
|
{
|
|
.name = "bfq.empty_time",
|
|
.private = offsetof(struct bfq_group, stats.empty_time),
|
|
.seq_show = bfqg_print_stat,
|
|
},
|
|
{
|
|
.name = "bfq.dequeue",
|
|
.private = offsetof(struct bfq_group, stats.dequeue),
|
|
.seq_show = bfqg_print_stat,
|
|
},
|
|
#endif /* CONFIG_BFQ_CGROUP_DEBUG */
|
|
{ } /* terminate */
|
|
};
|
|
|
|
struct cftype bfq_blkg_files[] = {
|
|
{
|
|
.name = "bfq.weight",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = bfq_io_show_weight,
|
|
.write = bfq_io_set_weight,
|
|
},
|
|
{} /* terminate */
|
|
};
|
|
|
|
#else /* CONFIG_BFQ_GROUP_IOSCHED */
|
|
|
|
void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
|
|
struct bfq_group *bfqg) {}
|
|
|
|
void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
|
|
{
|
|
struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
|
|
|
|
entity->weight = entity->new_weight;
|
|
entity->orig_weight = entity->new_weight;
|
|
if (bfqq) {
|
|
bfqq->ioprio = bfqq->new_ioprio;
|
|
bfqq->ioprio_class = bfqq->new_ioprio_class;
|
|
}
|
|
entity->sched_data = &bfqg->sched_data;
|
|
}
|
|
|
|
void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {}
|
|
|
|
void bfq_end_wr_async(struct bfq_data *bfqd)
|
|
{
|
|
bfq_end_wr_async_queues(bfqd, bfqd->root_group);
|
|
}
|
|
|
|
struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct blkcg *blkcg)
|
|
{
|
|
return bfqd->root_group;
|
|
}
|
|
|
|
struct bfq_group *bfqq_group(struct bfq_queue *bfqq)
|
|
{
|
|
return bfqq->bfqd->root_group;
|
|
}
|
|
|
|
void bfqg_and_blkg_get(struct bfq_group *bfqg) {}
|
|
|
|
void bfqg_and_blkg_put(struct bfq_group *bfqg) {}
|
|
|
|
struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
|
|
{
|
|
struct bfq_group *bfqg;
|
|
int i;
|
|
|
|
bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node);
|
|
if (!bfqg)
|
|
return NULL;
|
|
|
|
for (i = 0; i < BFQ_IOPRIO_CLASSES; i++)
|
|
bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT;
|
|
|
|
return bfqg;
|
|
}
|
|
#endif /* CONFIG_BFQ_GROUP_IOSCHED */
|