From: Will Deacon <will.deacon@arm.com>
To: Waiman Long <Waiman.Long@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
David Howells <dhowells@redhat.com>,
Dave Jones <davej@redhat.com>,
Clark Williams <williams@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH v2 optional 3/3] mutex: back out architecture specific check for negative mutex count
Date: Tue, 16 Apr 2013 11:05:05 +0100 [thread overview]
Message-ID: <20130416100505.GD31156@mudshark.cambridge.arm.com> (raw)
In-Reply-To: <1366036679-9702-4-git-send-email-Waiman.Long@hp.com>
On Mon, Apr 15, 2013 at 03:37:59PM +0100, Waiman Long wrote:
> If it is confirmed that all the supported architectures can allow a
> negative mutex count without incorrect behavior, we can then back
> out the architecture specific change and allow the mutex count to
> go to any negative number. That should further reduce contention for
> non-x86 architecture.
>
> If this is not the case, this patch should be dropped.
A good starting point might be to look at the asm-generic mutex
implementations, which clears up the majority of architectures. A cursory
glance at mutex-dec.h suggests that it's OK to me...
Will
next prev parent reply other threads:[~2013-04-16 10:05 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-15 14:37 [PATCH 0/3 v2] mutex: Improve mutex performance by doing less atomic-ops & better spinning Waiman Long
2013-04-15 14:37 ` [PATCH v2 1/3] mutex: Make more scalable by doing less atomic operations Waiman Long
2013-04-15 14:45 ` Rik van Riel
2013-04-15 14:37 ` [PATCH v2 2/3] mutex: Queue mutex spinners with MCS lock to reduce cacheline contention Waiman Long
2013-04-15 14:37 ` Waiman Long
2013-04-15 16:27 ` Rik van Riel
2013-04-16 4:24 ` Davidlohr Bueso
2013-04-16 12:05 ` Waiman Long
2013-04-16 9:10 ` Ingo Molnar
2013-04-16 14:26 ` Waiman Long
2013-04-17 7:50 ` Ingo Molnar
2013-04-17 7:50 ` Ingo Molnar
2013-04-15 14:37 ` [PATCH v2 optional 3/3] mutex: back out architecture specific check for negative mutex count Waiman Long
2013-04-15 14:37 ` Waiman Long
2013-04-16 10:05 ` Will Deacon [this message]
2013-04-16 12:10 ` Waiman Long
2013-04-16 9:12 ` [PATCH 0/3 v2] mutex: Improve mutex performance by doing less atomic-ops & better spinning Ingo Molnar
2013-04-16 9:12 ` Ingo Molnar
2013-04-16 11:49 ` Waiman Long
2013-04-16 13:09 ` Ingo Molnar
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