Messages in this thread | | | Subject | Re: [PATCH] locking: remove spin_lock_flags() etc | From | Waiman Long <> | Date | Mon, 25 Oct 2021 14:25:32 -0400 |
| |
On 10/25/21 11:44 AM, Arnd Bergmann wrote: > On Mon, Oct 25, 2021 at 5:28 PM Waiman Long <longman@redhat.com> wrote: >> On 10/25/21 9:06 AM, Arnd Bergmann wrote: >>> On s390, we pick between the cmpxchg() based directed-yield when >>> running on virtualized CPUs, and a normal qspinlock when running on a >>> dedicated CPU. >> I am not aware that s390 is using qspinlocks at all as I don't see >> ARCH_USE_QUEUED_SPINLOCKS being set anywhere under arch/s390. I only see >> that it uses a cmpxchg based spinlock. > Sorry, I should not have said "normal" here. See arch/s390/lib/spinlock.c > for their custom queued spinlocks as implemented in arch_spin_lock_queued(). > I don't know if that code actually does the same thing as the generic qspinlock, > but it seems at least similar.
Yes, you are right. Their queued lock code looks like a custom version of the pvqspinlock code.
Cheers, Longman
| |