Messages in this thread | | | Date | Tue, 4 May 2021 11:19:48 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] locking/qrwlock: queued_write_lock_slowpath() cleanup |
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On Tue, Apr 27, 2021 at 08:56:59AM +0100, Will Deacon wrote: > On Mon, Apr 26, 2021 at 02:50:17PM -0400, Waiman Long wrote: > > Make the code more readable by replacing the atomic_cmpxchg_acquire() > > by an equivalent atomic_try_cmpxchg_acquire() and change atomic_add() > > to atomic_or(). > > > > For architectures that use qrwlock, I do not find one that has an > > atomic_add() defined but not an atomic_or(). I guess it should be fine > > by changing atomic_add() to atomic_or(). > > > > Note that the previous use of atomic_add() isn't wrong as only one > > writer that is the wait_lock owner can set the waiting flag and the > > flag will be cleared later on when acquiring the write lock. > > Right, there's no functional change here. > > > Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> > > Signed-off-by: Waiman Long <longman@redhat.com>
> Acked-by: Will Deacon <will@kernel.org>
Thanks!
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