lkml.org 
[lkml]   [2020]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] scripts: coccicheck: Change default value for parallelism
Date
By default, coccicheck utilizes all available threads to implement
parallelisation. However, when hyperthreading is enabled, this leads
to all threads per core being occupied resulting in longer wall-clock
times and higher power consumption. Hence, to improve performance,
modify coccicheck to use only one thread per core atmost.

In the cases where the total number of threads is more than 8 and
hyperthreading is enabled, it was observed that optimum performance
is achieved around one-fourth of the total number of cores.
Modify the script further to accommodate this use case.

Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
---
scripts/coccicheck | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/scripts/coccicheck b/scripts/coccicheck
index e04d328210ac..dd228dcc915e 100755
--- a/scripts/coccicheck
+++ b/scripts/coccicheck
@@ -75,8 +75,17 @@ else
OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE"
fi

+ # Use only one thread per core by default if hyperthreading is enabled
+ THREADS_PER_CORE=$(lscpu | grep "Thread(s) per core: " | tr -cd [:digit:])
if [ -z "$J" ]; then
NPROC=$(getconf _NPROCESSORS_ONLN)
+ if [ $THREADS_PER_CORE -gt 1 -a $NPROC -gt 2 ] ; then
+ if [ $NPROC -gt 8 ] ; then
+ NPROC=$((NPROC/4))
+ else
+ NPROC=$((NPROC/2))
+ fi
+ fi
else
NPROC="$J"
fi
--
2.17.1
\
 
 \ /
  Last update: 2020-08-12 20:29    [W:0.061 / U:2.852 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site