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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-18 07:52:21 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-18 13:03:38 -0700 |
commit | dcf23ac3e846ca0cf626c155a0e3fcbbcf4fae8a (patch) | |
tree | bcec3946a19e79751a97280bed14a633ad1a8ff8 /Makefile | |
parent | 5076190daded2197f62fe92cf69674488be44175 (diff) | |
download | linux-dcf23ac3e846ca0cf626c155a0e3fcbbcf4fae8a.tar.gz linux-dcf23ac3e846ca0cf626c155a0e3fcbbcf4fae8a.tar.bz2 linux-dcf23ac3e846ca0cf626c155a0e3fcbbcf4fae8a.zip |
locks: reinstate locks_delete_block optimization
There is measurable performance impact in some synthetic tests due to
commit 6d390e4b5d48 (locks: fix a potential use-after-free problem when
wakeup a waiter). Fix the race condition instead by clearing the
fl_blocker pointer after the wake_up, using explicit acquire/release
semantics.
This does mean that we can no longer use the clearing of fl_blocker as
the wait condition, so switch the waiters over to checking whether the
fl_blocked_member list_head is empty.
Reviewed-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Fixes: 6d390e4b5d48 (locks: fix a potential use-after-free problem when wakeup a waiter)
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Makefile')
0 files changed, 0 insertions, 0 deletions