lkml.org 
[lkml]   [2023]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH mm-unstable] lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default
On Sat, 21 Jan 2023, Hyeonggon Yoo wrote:

>In workloads where this_cpu operations are frequently performed,
>enabling DEBUG_PREEMPT may result in significant increase in
>runtime overhead due to frequent invocation of
>__this_cpu_preempt_check() function.
>
>This can be demonstrated through benchmarks such as hackbench where this
>configuration results in a 10% reduction in performance, primarily due to
>the added overhead within memcg charging path.
>
>Therefore, do not to enable DEBUG_PREEMPT by default and make users aware
>of its potential impact on performance in some workloads.
>
>hackbench-process-sockets
> debug_preempt no_debug_preempt
>Amean 1 0.4743 ( 0.00%) 0.4295 * 9.45%*
>Amean 4 1.4191 ( 0.00%) 1.2650 * 10.86%*
>Amean 7 2.2677 ( 0.00%) 2.0094 * 11.39%*
>Amean 12 3.6821 ( 0.00%) 3.2115 * 12.78%*
>Amean 21 6.6752 ( 0.00%) 5.7956 * 13.18%*
>Amean 30 9.6646 ( 0.00%) 8.5197 * 11.85%*
>Amean 48 15.3363 ( 0.00%) 13.5559 * 11.61%*
>Amean 79 24.8603 ( 0.00%) 22.0597 * 11.27%*
>Amean 96 30.1240 ( 0.00%) 26.8073 * 11.01%*
>
>Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>

Acked-by: Davidlohr Bueso <dave@stgolabs.net>

\
 
 \ /
  Last update: 2023-03-27 00:06    [W:0.139 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site