From: Arnd Bergmann <arnd@kernel.org>
To: Waiman Long <longman@redhat.com>
Cc: linux-ia64@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
Paul Mackerras <paulus@samba.org>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Will Deacon <will@kernel.org>, Jonas Bonn <jonas@southpole.se>,
linux-s390 <linux-s390@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Helge Deller <deller@gmx.de>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Ingo Molnar <mingo@redhat.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Boqun Feng <boqun.feng@gmail.com>,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
Openrisc <openrisc@lists.librecores.org>,
Stafford Horne <shorne@gmail.com>,
Parisc List <linux-parisc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH] locking: remove spin_lock_flags() etc
Date: Mon, 25 Oct 2021 17:44:26 +0200 [thread overview]
Message-ID: <CAK8P3a3JEBF-dEg0iVThMMRNK3CDxY+mRtTeStMusycnethO_g@mail.gmail.com> (raw)
In-Reply-To: <2413f412-a390-bbc0-e848-e2a77d1f0ab3@redhat.com>
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.
Arnd
next prev parent reply other threads:[~2021-10-25 15:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-22 11:59 [PATCH] locking: remove spin_lock_flags() etc Arnd Bergmann
2021-10-22 14:10 ` Helge Deller
2021-10-23 1:37 ` Waiman Long
2021-10-23 16:04 ` Arnd Bergmann
2021-10-25 9:57 ` Peter Zijlstra
2021-10-25 10:06 ` Peter Zijlstra
2021-10-25 13:06 ` Arnd Bergmann
2021-10-25 14:33 ` Peter Zijlstra
2021-10-27 12:01 ` Michael Ellerman
2021-10-25 15:28 ` Waiman Long
2021-10-25 15:44 ` Arnd Bergmann [this message]
2021-10-25 18:25 ` Waiman Long
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