diff options
| author |   Will Deacon <will.deacon@arm.com> | 2017-10-24 11:22:48 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-10-24 13:17:33 +0200 |
| commit | 506458efaf153c1ea480591c5602a5a3ba5a3b76 (patch) | |
| tree | c4ac0a89bf23993036720ec8883fff0740bf9019 /kernel/events | |
| parent | locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE() (diff) | |
| download | linux-dev-506458efaf153c1ea480591c5602a5a3ba5a3b76.tar.xz linux-dev-506458efaf153c1ea480591c5602a5a3ba5a3b76.zip | |
locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it
can be used instead of lockless_dereference() without any change in
semantics.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 9d93db81fa36..824a583079a1 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4231,7 +4231,7 @@ static void perf_remove_from_owner(struct perf_event *event) * indeed free this event, otherwise we need to serialize on * owner->perf_event_mutex. */ - owner = lockless_dereference(event->owner); + owner = READ_ONCE(event->owner); if (owner) { /* * Since delayed_put_task_struct() also drops the last @@ -4328,7 +4328,7 @@ again: * Cannot change, child events are not migrated, see the * comment with perf_event_ctx_lock_nested(). */ - ctx = lockless_dereference(child->ctx); + ctx = READ_ONCE(child->ctx); /* * Since child_mutex nests inside ctx::mutex, we must jump * through hoops. We start by grabbing a reference on the ctx. |