diff options
| author | Jens Axboe <axboe@kernel.dk> | 2022-11-30 08:25:46 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-11-30 08:25:46 -0700 |
| commit | c62256dda37133a48d56cecc15e4a4d527d4cc46 (patch) | |
| tree | ccc2be0058d65a201ba20d8b297d4e34cb0a9687 | |
| parent | 8d283ee62b077968e218531b24260e1cc51bd484 (diff) | |
| download | linux-c62256dda37133a48d56cecc15e4a4d527d4cc46.tar.bz2 | |
Revert "blk-cgroup: Flush stats at blkgs destruction path"
This reverts commit dae590a6c96c799434e0ff8156ef29b88c257e60.
We've had a few reports on this causing a crash at boot time, because
of a reference issue. While this problem seemginly did exist before
the patch and needs solving separately, this patch makes it a lot
easier to trigger.
Link: https://lore.kernel.org/linux-block/CA+QYu4oxiRKC6hJ7F27whXy-PRBx=Tvb+-7TQTONN8qTtV3aDA@mail.gmail.com/
Link: https://lore.kernel.org/linux-block/69af7ccb-6901-c84c-0e95-5682ccfb750c@acm.org/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-cgroup.c | 15 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 1 | ||||
| -rw-r--r-- | kernel/cgroup/rstat.c | 20 |
3 files changed, 1 insertions, 35 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 57941d2a8ba3..3e03c0d13253 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1084,12 +1084,10 @@ struct list_head *blkcg_get_cgwb_list(struct cgroup_subsys_state *css) */ static void blkcg_destroy_blkgs(struct blkcg *blkcg) { - int cpu; - might_sleep(); - css_get(&blkcg->css); spin_lock_irq(&blkcg->lock); + while (!hlist_empty(&blkcg->blkg_list)) { struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first, struct blkcg_gq, blkcg_node); @@ -1112,17 +1110,6 @@ static void blkcg_destroy_blkgs(struct blkcg *blkcg) } spin_unlock_irq(&blkcg->lock); - - /* - * Flush all the non-empty percpu lockless lists. - */ - for_each_possible_cpu(cpu) { - struct llist_head *lhead = per_cpu_ptr(blkcg->lhead, cpu); - - if (!llist_empty(lhead)) - cgroup_rstat_css_cpu_flush(&blkcg->css, cpu); - } - css_put(&blkcg->css); } /** diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 6c4e66b3fa84..528bd44b59e2 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -766,7 +766,6 @@ void cgroup_rstat_flush(struct cgroup *cgrp); void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp); void cgroup_rstat_flush_hold(struct cgroup *cgrp); void cgroup_rstat_flush_release(void); -void cgroup_rstat_css_cpu_flush(struct cgroup_subsys_state *css, int cpu); /* * Basic resource stats. diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index 910e633869b0..793ecff29038 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -281,26 +281,6 @@ void cgroup_rstat_flush_release(void) spin_unlock_irq(&cgroup_rstat_lock); } -/** - * cgroup_rstat_css_cpu_flush - flush stats for the given css and cpu - * @css: target css to be flush - * @cpu: the cpu that holds the stats to be flush - * - * A lightweight rstat flush operation for a given css and cpu. - * Only the cpu_lock is being held for mutual exclusion, the cgroup_rstat_lock - * isn't used. - */ -void cgroup_rstat_css_cpu_flush(struct cgroup_subsys_state *css, int cpu) -{ - raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); - - raw_spin_lock_irq(cpu_lock); - rcu_read_lock(); - css->ss->css_rstat_flush(css, cpu); - rcu_read_unlock(); - raw_spin_unlock_irq(cpu_lock); -} - int cgroup_rstat_init(struct cgroup *cgrp) { int cpu; |