From: "Tim Chen" <tim.c.chen@linux.intel.com>
To: "Ingo Molnar" <mingo@elte.hu>
Cc: "Tim Chen" <tim.c.chen@linux.intel.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
peterz@infradead.org, "Andrew Morton" <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, "Andi Kleen" <ak@linux.intel.com>,
"Tony Luck" <tony.luck@intel.com>
Subject: Re: [PATCH 1/1] mutex: prevent optimistic spinning from spinning longer than neccessary (Repost)
Date: Thu, 19 Aug 2010 15:24:46 -0700 (PDT) [thread overview]
Message-ID: <1877.10.21.68.23.1282256686.squirrel@linux.intel.com> (raw)
In-Reply-To: <20100819110511.GA16264@elte.hu>
> Ingo wrote:
>
> These are some rather impressive speedups!
>
> Have you tried to see what performance effects this change has on
smaller
> boxes? Just to see what flip side (if any) this change has.
>
I've done similar experiments with 2.6.35 kernel on smaller boxes. One is
on a dual-socket Westmere box (12 cores total, with HT). Another
experiment is on an old dual-socket Core 2 box (4 cores total, no HT)
On the 12-core Westmere box, I see a 250% increase for Ingo's mutex-test
program with my mutex patch but no significant difference in aim7's
fserver workload.
On the 4-core Core 2 box, I see the difference with the patch for both
mutex-test and aim7 fserver are negligible.
So far, it seems like the patch has not caused regression on smaller
systems. We'll put it through more workloads to check.
Tim
next prev parent reply other threads:[~2010-08-19 22:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-18 22:00 [PATCH 1/1] mutex: prevent optimistic spinning from spinning longer than neccessary (Repost) Tim Chen
2010-08-19 11:05 ` Ingo Molnar
2010-08-19 22:24 ` Tim Chen [this message]
2010-08-20 13:19 ` Ingo Molnar
2010-08-20 16:54 ` Tim Chen
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