lkml.org 
[lkml]   [2020]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [x86/entry] 8c5045f89b: will-it-scale.per_process_ops -12.9% regression
On Fri, Mar 27, 2020 at 03:40:02PM +0800, kernel test robot wrote:
> Greeting,
>
> FYI, we noticed a -12.9% regression of will-it-scale.per_process_ops due to commit:
>
>
> commit: 8c5045f89b181a4412b698cafc9dc257192a3a65 ("x86/entry: Enable random_kstack_offset support")
> https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git kspp/stack/offset/agnostic/v1
>
> in testcase: will-it-scale
> on test machine: 288 threads Intel(R) Xeon Phi(TM) CPU 7295 @ 1.50GHz with 80G memory
> with following parameters:
>
> nr_task: 100%
> mode: process
> test: lseek1
> cpufreq_governor: performance
> ucode: 0x11
>
> test-description: Will It Scale takes a testcase and runs it from 1 through to n parallel copies to see if the testcase will scale. It builds both a process and threads based test in order to see any differences between the two.
> test-url: https://github.com/antonblanchard/will-it-scale

Whoa. I'll take a closer look. I fail to understand how this could be
happening. In this CONFIG the changes are a NOP. And that would be
true for both process and thread. O_o

--
Kees Cook

\
 
 \ /
  Last update: 2020-03-28 23:20    [W:0.041 / U:1.884 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site