From: Pekka Enberg <penberg@kernel.org>
To: Christoph Lameter <cl@linux.com>
Cc: Marcin Slusarz <marcin.slusarz@gmail.com>,
Matt Mackall <mpm@selenic.com>,
LKML <linux-kernel@vger.kernel.org>,
rientjes@google.com, linux-mm@kvack.org
Subject: Re: [PATCH] slub: reduce overhead of slub_debug
Date: Thu, 07 Jul 2011 21:52:51 +0300 [thread overview]
Message-ID: <1310064771.21902.55.camel@jaguar> (raw)
In-Reply-To: <alpine.DEB.2.00.1107071314320.21719@router.home>
On Thu, 7 Jul 2011, Pekka Enberg wrote:
> > Looks good to me. Christoph, David, ?
On Thu, 2011-07-07 at 13:17 -0500, Christoph Lameter wrote:
> The reason debug code is there is because it is useless overhead typically
> not needed. There is no point in optimizing the code that is not run in
> production environments unless there are gross performance issues that
> make debugging difficult. A performance patch for debugging would have to
> cause significant performance improvements. This patch does not do that
> nor was there such an issue to be addressed in the first place.
Is there something technically wrong with the patch? Quoting the patch
email:
(Compiling some project with different options)
make -j12 make clean
slub_debug disabled: 1m 27s 1.2 s
slub_debug enabled: 1m 46s 7.6 s
slub_debug enabled + this patch: 1m 33s 3.2 s
check_bytes still shows up high, but not always at the top.
That's significant enough speedup for me!
Pekka
WARNING: multiple messages have this Message-ID (diff)
From: Pekka Enberg <penberg@kernel.org>
To: Christoph Lameter <cl@linux.com>
Cc: Marcin Slusarz <marcin.slusarz@gmail.com>,
Matt Mackall <mpm@selenic.com>,
LKML <linux-kernel@vger.kernel.org>,
rientjes@google.com, linux-mm@kvack.org
Subject: Re: [PATCH] slub: reduce overhead of slub_debug
Date: Thu, 07 Jul 2011 21:52:51 +0300 [thread overview]
Message-ID: <1310064771.21902.55.camel@jaguar> (raw)
In-Reply-To: <alpine.DEB.2.00.1107071314320.21719@router.home>
On Thu, 7 Jul 2011, Pekka Enberg wrote:
> > Looks good to me. Christoph, David, ?
On Thu, 2011-07-07 at 13:17 -0500, Christoph Lameter wrote:
> The reason debug code is there is because it is useless overhead typically
> not needed. There is no point in optimizing the code that is not run in
> production environments unless there are gross performance issues that
> make debugging difficult. A performance patch for debugging would have to
> cause significant performance improvements. This patch does not do that
> nor was there such an issue to be addressed in the first place.
Is there something technically wrong with the patch? Quoting the patch
email:
(Compiling some project with different options)
make -j12 make clean
slub_debug disabled: 1m 27s 1.2 s
slub_debug enabled: 1m 46s 7.6 s
slub_debug enabled + this patch: 1m 33s 3.2 s
check_bytes still shows up high, but not always at the top.
That's significant enough speedup for me!
Pekka
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next prev parent reply other threads:[~2011-07-07 18:52 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-26 19:39 [PATCH] slub: reduce overhead of slub_debug Marcin Slusarz
2011-06-26 19:39 ` Marcin Slusarz
2011-06-28 19:32 ` Christoph Lameter
2011-06-28 19:32 ` Christoph Lameter
2011-06-28 19:40 ` David Daney
2011-06-28 19:40 ` David Daney
2011-06-28 20:58 ` David Rientjes
2011-06-28 20:58 ` David Rientjes
2011-06-28 21:04 ` Ben Greear
2011-06-28 21:04 ` Ben Greear
2011-06-28 21:10 ` David Rientjes
2011-06-28 21:10 ` David Rientjes
2011-06-28 21:16 ` Dave Jones
2011-06-28 21:16 ` Dave Jones
2011-07-07 18:07 ` Pekka Enberg
2011-07-07 18:07 ` Pekka Enberg
2011-07-07 18:17 ` Christoph Lameter
2011-07-07 18:17 ` Christoph Lameter
2011-07-07 18:30 ` Ben Greear
2011-07-07 18:30 ` Ben Greear
2011-07-07 18:42 ` Christoph Lameter
2011-07-07 18:42 ` Christoph Lameter
2011-07-07 18:54 ` Ben Greear
2011-07-07 18:54 ` Ben Greear
2011-07-07 18:30 ` Matt Mackall
2011-07-07 18:30 ` Matt Mackall
2011-07-07 18:52 ` Pekka Enberg [this message]
2011-07-07 18:52 ` Pekka Enberg
2011-07-07 18:55 ` Matt Mackall
2011-07-07 18:55 ` Matt Mackall
2011-07-07 19:12 ` Christoph Lameter
2011-07-07 19:12 ` Christoph Lameter
2011-07-07 19:21 ` David Miller
2011-07-07 19:21 ` David Miller
2011-07-07 19:49 ` Pekka Enberg
2011-07-07 19:49 ` Pekka Enberg
2011-07-07 20:12 ` Christoph Lameter
2011-07-07 20:12 ` Christoph Lameter
2011-07-08 5:23 ` Andi Kleen
2011-07-08 5:23 ` Andi Kleen
2011-07-08 17:41 ` Christoph Lameter
2011-07-08 17:41 ` Christoph Lameter
2011-07-08 5:38 ` Pekka Enberg
2011-07-08 5:38 ` Pekka Enberg
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