From: Ingo Molnar <mingo@kernel.org>
To: Waiman Long <Waiman.Long@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
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>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrew Morton <akpm@linux-foundation.org>,
"Norton, Scott J" <scott.norton@hp.com>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH RFC 1/3] mutex: Make more scalable by doing less atomic operations
Date: Wed, 10 Apr 2013 12:31:44 +0200 [thread overview]
Message-ID: <20130410103144.GC28505@gmail.com> (raw)
In-Reply-To: <5163042F.9000404@hp.com>
* Waiman Long <Waiman.Long@hp.com> wrote:
> > That said, the MUTEX_SHOULD_XCHG_COUNT macro should die. Why shouldn't all
> > architectures just consider negative counts to be locked? It doesn't matter
> > that some might only ever see -1.
>
> I think so too. However, I don't have the machines to test out other
> architectures. The MUTEX_SHOULD_XCHG_COUNT is just a safety measure to make sure
> that my code won't screw up the kernel in other architectures. Once it is
> confirmed that a negative count other than -1 is fine for all the other
> architectures, the macro can certainly go.
I'd suggest to just remove it in an additional patch, Cc:-ing
linux-arch@vger.kernel.org. The change is very likely to be fine, if not then it's
easy to revert it.
Thanks,
Ingo
next prev parent reply other threads:[~2013-04-10 10:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-04 14:54 [PATCH RFC 0/3] mutex: Improve mutex performance by doing less atomic-ops & spinning Waiman Long
2013-04-04 14:54 ` [PATCH RFC 1/3] mutex: Make more scalable by doing less atomic operations Waiman Long
2013-04-08 12:42 ` Ingo Molnar
2013-04-08 14:38 ` Linus Torvalds
2013-04-08 15:09 ` Ingo Molnar
2013-04-08 17:53 ` Waiman Long
2013-04-10 10:31 ` Ingo Molnar [this message]
2013-04-10 15:52 ` Waiman Long
2013-04-10 17:16 ` Ingo Molnar
2013-04-10 21:26 ` Waiman Long
2013-04-11 9:07 ` Ingo Molnar
2013-04-10 14:09 ` Robin Holt
2013-04-10 15:46 ` Linus Torvalds
2013-04-08 17:42 ` Waiman Long
2013-04-10 10:28 ` Ingo Molnar
2013-04-10 15:47 ` Waiman Long
2013-04-04 14:54 ` [PATCH RFC 2/3] mutex: restrict mutex spinning to only one task per mutex Waiman Long
2013-04-04 14:54 ` [PATCH RFC 3/3] mutex: dynamically disable mutex spinning at high load Waiman Long
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