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| author | Baolin Wang <baolin.wang@linux.alibaba.com> | 2021-01-28 13:58:15 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-01-28 07:31:48 -0700 |
| commit | 6c635caef410aa757befbd8857c1eadde5cc22ed (patch) | |
| tree | a5aabfeaa5640f9a8b98cd0cce6e69a386d575ab /block/partitions/core.c | |
| parent | 8dc932d3e8afb65e12eba7495f046c83884c49bf (diff) | |
| download | lwn-6c635caef410aa757befbd8857c1eadde5cc22ed.tar.gz lwn-6c635caef410aa757befbd8857c1eadde5cc22ed.zip | |
blk-cgroup: Use cond_resched() when destroy blkgs
On !PREEMPT kernel, we can get below softlockup when doing stress
testing with creating and destroying block cgroup repeatly. The
reason is it may take a long time to acquire the queue's lock in
the loop of blkcg_destroy_blkgs(), or the system can accumulate a
huge number of blkgs in pathological cases. We can add a need_resched()
check on each loop and release locks and do cond_resched() if true
to avoid this issue, since the blkcg_destroy_blkgs() is not called
from atomic contexts.
[ 4757.010308] watchdog: BUG: soft lockup - CPU#11 stuck for 94s!
[ 4757.010698] Call trace:
[ 4757.010700] blkcg_destroy_blkgs+0x68/0x150
[ 4757.010701] cgwb_release_workfn+0x104/0x158
[ 4757.010702] process_one_work+0x1bc/0x3f0
[ 4757.010704] worker_thread+0x164/0x468
[ 4757.010705] kthread+0x108/0x138
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/partitions/core.c')
0 files changed, 0 insertions, 0 deletions