On Wed, Aug 28, 2024 at 01:52:33PM GMT, Michael Ellerman wrote:
> "Nysal Jan K.A." writes:
> > If an interrupt occurs in queued_spin_lock_slowpath() after we increment
> > qnodesp->count and before node->lock is initialized, another CPU might
> > see stale lock values in get_tail_qnode(). If the s
On Wed, Aug 28, 2024 at 01:19:46PM GMT, Nicholas Piggin wrote:
> What probably makes it really difficult to hit is that I think both
> locks A and B need contention from other sources to push them into
> queueing slow path. I guess that's omitted for brevity in the flow
> above, which is fine.
>
"Nysal Jan K.A." writes:
> If an interrupt occurs in queued_spin_lock_slowpath() after we increment
> qnodesp->count and before node->lock is initialized, another CPU might
> see stale lock values in get_tail_qnode(). If the stale lock value happens
> to match the lock on that CPU, then we write t
Hey Nysal,
This is really good debugging, and a nice write up.
On Mon Aug 26, 2024 at 6:12 PM AEST, Nysal Jan K.A. wrote:
> If an interrupt occurs in queued_spin_lock_slowpath() after we increment
> qnodesp->count and before node->lock is initialized, another CPU might
> see stale lock values in
