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From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>, Pekka Enberg <penberg@cs.helsinki.fi>,
	alex.shi@intel.com,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Ma, Ling" <ling.ma@intel.com>,
	"Chen, Tim C" <tim.c.chen@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: hackbench regression due to commit 9dfc6e68bfe6e
Date: Wed, 07 Apr 2010 10:20:40 +0800	[thread overview]
Message-ID: <1270606840.2078.231.camel@ymzhang.sh.intel.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1004061552500.19151@router.home>

On Tue, 2010-04-06 at 15:55 -0500, Christoph Lameter wrote:
> We cannot reproduce the issue here. Our tests here (dual quad dell) show a
> performance increase in hackbench instead.
I run hackbench on many machines. The regression exists on Nehalem machine
(dual sockets, 2*4*2 logical cpu) and a tigerton (4 socket, 4*4 logical cpu)
machines. I tried it on a dual quad core2 machine and it does like what you said.

The regression also exists on 2 new-generation Nehalem (dual socket 2*6*2 logical cpu)
machines.

It seems hyperthreading cpu has more chances to trigger it.

> 
> Linux 2.6.33.2 #2 SMP Mon Apr 5 11:30:56 CDT 2010 x86_64 GNU/Linux
> ./hackbench 100 process 200000
> Running with 100*40 (== 4000) tasks.
> Time: 3102.142
> ./hackbench 100 process 20000
> Running with 100*40 (== 4000) tasks.
> Time: 308.731
> ./hackbench 100 process 20000
> Running with 100*40 (== 4000) tasks.
> Time: 311.591
> ./hackbench 100 process 20000
> Running with 100*40 (== 4000) tasks.
> Time: 310.200
> ./hackbench 10 process 20000
> Running with 10*40 (== 400) tasks.
> Time: 38.048
> ./hackbench 10 process 20000
> Running with 10*40 (== 400) tasks.
> Time: 44.711
> ./hackbench 10 process 20000
> Running with 10*40 (== 400) tasks.
> Time: 39.407
> ./hackbench 1 process 20000
> Running with 1*40 (== 40) tasks.
> Time: 9.411
> ./hackbench 1 process 20000
> Running with 1*40 (== 40) tasks.
> Time: 8.765
> ./hackbench 1 process 20000
> Running with 1*40 (== 40) tasks.
> Time: 8.822
> 
> Linux 2.6.34-rc3 #1 SMP Tue Apr 6 13:30:34 CDT 2010 x86_64 GNU/Linux
> ./hackbench 100 process 200000
> Running with 100*40 (== 4000) tasks.
> Time: 3003.578
> ./hackbench 100 process 20000
> Running with 100*40 (== 4000) tasks.
> Time: 300.289
> ./hackbench 100 process 20000
> Running with 100*40 (== 4000) tasks.
> Time: 301.462
> ./hackbench 100 process 20000
> Running with 100*40 (== 4000) tasks.
> Time: 301.173
> ./hackbench 10 process 20000
> Running with 10*40 (== 400) tasks.
> Time: 41.191
> ./hackbench 10 process 20000
> Running with 10*40 (== 400) tasks.
> Time: 41.964
> ./hackbench 10 process 20000
> Running with 10*40 (== 400) tasks.
> Time: 41.470
> ./hackbench 1 process 20000
> Running with 1*40 (== 40) tasks.
> Time: 8.829
> ./hackbench 1 process 20000
> Running with 1*40 (== 40) tasks.
> Time: 9.166
> ./hackbench 1 process 20000
> Running with 1*40 (== 40) tasks.
> Time: 8.681
> 
> 



  parent reply	other threads:[~2010-04-07  2:18 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-25  8:40 hackbench regression due to commit 9dfc6e68bfe6e Alex Shi
2010-03-25 14:49 ` Christoph Lameter
2010-03-26  2:35   ` Alex Shi
2010-04-01  9:29     ` Zhang, Yanmin
2010-04-01 15:53       ` Christoph Lameter
2010-04-02  8:06         ` Zhang, Yanmin
2010-04-05 13:54           ` Christoph Lameter
2010-04-05 17:30             ` Pekka Enberg
2010-04-06  1:27               ` Tejun Heo
2010-04-06  8:28                 ` Zhang, Yanmin
2010-04-06 15:41                   ` Christoph Lameter
2010-04-06 20:55                     ` Christoph Lameter
2010-04-06 22:10                       ` Eric Dumazet
2010-04-07  2:34                         ` Zhang, Yanmin
2010-04-07  6:39                           ` Eric Dumazet
2010-04-07  9:07                             ` Zhang, Yanmin
2010-04-07  9:20                               ` Eric Dumazet
2010-04-07 10:47                           ` Pekka Enberg
2010-04-07 16:30                           ` Christoph Lameter
2010-04-07 16:43                           ` Christoph Lameter
2010-04-07 16:49                             ` Pekka Enberg
2010-04-07 16:52                               ` Pekka Enberg
2010-04-07 18:20                                 ` Christoph Lameter
2010-04-07 18:25                                   ` Pekka Enberg
2010-04-07 19:30                                     ` Christoph Lameter
2010-04-07 18:38                                   ` Eric Dumazet
2010-04-08  1:05                                     ` Zhang, Yanmin
2010-04-08  4:59                                       ` Eric Dumazet
2010-04-08  5:39                                         ` Eric Dumazet
2010-04-08  7:00                                           ` Eric Dumazet
2010-04-08  7:05                                             ` David Miller
2010-04-08  7:20                                               ` David Miller
2010-04-08  7:25                                               ` Eric Dumazet
2010-04-08  7:54                                             ` Zhang, Yanmin
2010-04-08  7:54                                               ` Eric Dumazet
2010-04-08  8:09                                                 ` Eric Dumazet
2010-04-08 15:34                                           ` Christoph Lameter
2010-04-08 15:52                                             ` Eric Dumazet
2010-04-07 18:18                               ` Christoph Lameter
2010-04-08  7:18                             ` Zhang, Yanmin
2010-04-07  2:20                       ` Zhang, Yanmin [this message]
2010-04-07  0:58                     ` Zhang, Yanmin

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