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From: Ingo Molnar <mingo@elte.hu>
To: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: Jiri Kosina <jkosina@suse.cz>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org
Subject: Re: What is the performance when using frame pointers in the kernel?
Date: Sat, 5 Dec 2009 08:02:49 +0100	[thread overview]
Message-ID: <20091205070249.GA23330@elte.hu> (raw)
In-Reply-To: <alpine.DEB.2.00.0912041024500.16957@p34.internal.lan>


* Justin Piszcz <jpiszcz@lucidpixels.com> wrote:

> On Fri, 4 Dec 2009, Jiri Kosina wrote:
> 
> >On Thu, 3 Dec 2009, Peter Zijlstra wrote:
> >
> >>>What is the performance hit when the kernel is compiled with frame
> >>>pointers?
> >>
> >>build both kernels and run your favourite workload to find out.
> >
> >But generally speaking, frame pointers impose quite some performance
> >penalty indeed. lmbench syscall microbenchmark can give you some hint. I
> >expect you'll see approx. 10% performance increase for various syscalls if
> >you disable them, as that's what we have measured lately.
> >
> >-- 
> >Jiri Kosina
> >SUSE Labs, Novell Inc.
> >
> 
> Thanks for the response.. Good to know.

I dont buy the 10% without seeing precise measurement results. 1-2% 
maybe, in some cases.

	Ingo

  reply	other threads:[~2009-12-05  7:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-03 17:36 What is the performance when using frame pointers in the kernel? Justin Piszcz
2009-12-03 19:28 ` Peter Zijlstra
2009-12-04 13:23   ` Jiri Kosina
2009-12-04 15:25     ` Justin Piszcz
2009-12-05  7:02       ` Ingo Molnar [this message]
2009-12-06 22:31     ` Andi Kleen

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