linux-kernel - Re: hackbench regression due to commit 9dfc6e68bfe6e

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 07 Apr 2010 10:20:40 +0800
From:	"Zhang, Yanmin" <yanmin_zhang@...ux.intel.com>
To:	Christoph Lameter <cl@...ux-foundation.org>
Cc:	Tejun Heo <tj@...nel.org>, Pekka Enberg <penberg@...helsinki.fi>,
	alex.shi@...el.com,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"Ma, Ling" <ling.ma@...el.com>,
	"Chen, Tim C" <tim.c.chen@...el.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: hackbench regression due to commit 9dfc6e68bfe6e

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
> 
> 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/