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| author | Wei Fang <fangwei1@huawei.com> | 2016-07-06 11:32:20 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-16 09:30:50 +0200 |
| commit | 92f71339bceeda3a13b71e9663bf422bf3d3e941 (patch) | |
| tree | 4a1656a7be1c687252fdd5856c2726c153ef273b /crypto | |
| parent | b6e0a217f621c62a2abd3ce4c6ae8146c8122e98 (diff) | |
fs/dcache.c: avoid soft-lockup in dput()
commit 47be61845c775643f1aa4d2a54343549f943c94c upstream.
We triggered soft-lockup under stress test which
open/access/write/close one file concurrently on more than
five different CPUs:
WARN: soft lockup - CPU#0 stuck for 11s! [who:30631]
...
[<ffffffc0003986f8>] dput+0x100/0x298
[<ffffffc00038c2dc>] terminate_walk+0x4c/0x60
[<ffffffc00038f56c>] path_lookupat+0x5cc/0x7a8
[<ffffffc00038f780>] filename_lookup+0x38/0xf0
[<ffffffc000391180>] user_path_at_empty+0x78/0xd0
[<ffffffc0003911f4>] user_path_at+0x1c/0x28
[<ffffffc00037d4fc>] SyS_faccessat+0xb4/0x230
->d_lock trylock may failed many times because of concurrently
operations, and dput() may execute a long time.
Fix this by replacing cpu_relax() with cond_resched().
dput() used to be sleepable, so make it sleepable again
should be safe.
Signed-off-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto')
0 files changed, 0 insertions, 0 deletions