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author | Joe Perches <joe@perches.com> | 2015-06-26 01:02:46 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-26 03:00:41 +0300 |
commit | cb426e99ff9225e94fb56bd4c5cfcce8b78a3904 (patch) | |
tree | a7e47c66d32182613e9c9735ae32e48421b24b2e /fs/ext4/extents_status.c | |
parent | cbdc281019b8c5c905ef597511471b18e0fd4a15 (diff) | |
download | linux-cb426e99ff9225e94fb56bd4c5cfcce8b78a3904.tar.xz |
checkpatch: check for uncommented waitqueue_active()
Linus sayeth:
: Pretty much every single time people use this "if
: (waitqueue_active())" model, it tends to be a bug, because it means
: that there is zero serialization with people who are just about to go
: to sleep. It's fundamentally racy against all the "wait_event()" loops
: that carefully do memory barriers between testing conditions and going
: to sleep, because the memory barriers now don't exist on the waking
: side.
:
: So I'm making a new rule: if you use waitqueue_active(), I want an
: explanation for why it's not racy with the waiter. A big comment about
: the memory ordering, or about higher-level locks that are held by the
: caller, or something.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ext4/extents_status.c')
0 files changed, 0 insertions, 0 deletions