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| author | Li Nan <linan122@huawei.com> | 2024-04-19 17:32:57 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-04-19 08:06:24 -0600 |
| commit | 01bc4fda9ea0a6b52f12326486f07a4910666cf6 (patch) | |
| tree | 7279bbb793c22123882ec2a49b94e357f3eef3e8 /block/blk-iocost.c | |
| parent | 752863bddacab6b5c5164b1df8c8b2e3a175ee28 (diff) | |
| download | lwn-01bc4fda9ea0a6b52f12326486f07a4910666cf6.tar.gz lwn-01bc4fda9ea0a6b52f12326486f07a4910666cf6.zip | |
blk-iocost: do not WARN if iocg was already offlined
In iocg_pay_debt(), warn is triggered if 'active_list' is empty, which
is intended to confirm iocg is active when it has debt. However, warn
can be triggered during a blkcg or disk removal, if iocg_waitq_timer_fn()
is run at that time:
WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190
Call trace:
iocg_pay_debt+0x14c/0x190
iocg_kick_waitq+0x438/0x4c0
iocg_waitq_timer_fn+0xd8/0x130
__run_hrtimer+0x144/0x45c
__hrtimer_run_queues+0x16c/0x244
hrtimer_interrupt+0x2cc/0x7b0
The warn in this situation is meaningless. Since this iocg is being
removed, the state of the 'active_list' is irrelevant, and 'waitq_timer'
is canceled after removing 'active_list' in ioc_pd_free(), which ensures
iocg is freed after iocg_waitq_timer_fn() returns.
Therefore, add the check if iocg was already offlined to avoid warn
when removing a blkcg or disk.
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240419093257.3004211-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iocost.c')
| -rw-r--r-- | block/blk-iocost.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index baa20c85799d..690ca99dfaca 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1439,8 +1439,11 @@ static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay, lockdep_assert_held(&iocg->ioc->lock); lockdep_assert_held(&iocg->waitq.lock); - /* make sure that nobody messed with @iocg */ - WARN_ON_ONCE(list_empty(&iocg->active_list)); + /* + * make sure that nobody messed with @iocg. Check iocg->pd.online + * to avoid warn when removing blkcg or disk. + */ + WARN_ON_ONCE(list_empty(&iocg->active_list) && iocg->pd.online); WARN_ON_ONCE(iocg->inuse > 1); iocg->abs_vdebt -= min(abs_vpay, iocg->abs_vdebt); |