Messages in this thread | | | From | Waiman Long <> | Subject | Re: [PATCH] locking/qspinlock: Fix typo of lock word transition in the uncontended case | Date | Mon, 9 Aug 2021 12:22:31 -0400 |
| |
On 8/9/21 9:40 AM, Will Deacon wrote: > On Thu, Jul 15, 2021 at 11:08:47AM +0800, Zenghui Yu wrote: >> If the queue head is the only one in the queue and nobody is concurrently >> setting PENDING bit, the uncontended transition should be n,0,0 -> 0,0,1. >> >> Fix the typo. >> >> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> >> --- >> kernel/locking/qspinlock.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c >> index cbff6ba53d56..591835415698 100644 >> --- a/kernel/locking/qspinlock.c >> +++ b/kernel/locking/qspinlock.c >> @@ -355,7 +355,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) >> * If we observe contention, there is a concurrent locker. >> * >> * Undo and queue; our setting of PENDING might have made the >> - * n,0,0 -> 0,0,0 transition fail and it will now be waiting >> + * n,0,0 -> 0,0,1 transition fail and it will now be waiting >> * on @next to become !NULL. >> */ > I think this is an important typo fix as you're right that we don't > transition directly from having a waitqueue installed in the tail straight > to an unlocked state. > > Acked-by: Will Deacon <will@kernel.org> > > Then again, I acked the patch introducing this comment so what do I know?
We usually focus more on the actual code than the associated comment. I am not surprise we may miss that. I do agree that the proposed change is better.
Acked-by: Waiman Long <longman@redhat.com>
| |