Commit 25659790 authored Jun 23, 2024 by Hui Tang

sched: ARM64 enables SIS_PROP and disables SIS_UTIL"

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IA7CCA


CVE: NA

--------------------------------

We find the commit bb29df9f ("sched/fair: Introduce SIS_UTIL to
search idle CPU..."), which cause performance degradation
with Unixbench pipe-base contextswich case tested on Kunpeng 920B.

Test case: ./Run context1 -c `nproc` -i 3
Unixbench results (Pipe-based_Context_Switching):
baseline    patched
  4.5w       8.5w

Test on Kunpeng 920B

Fixes: bb29df9f ("sched/fair: Introduce SIS_UTIL to search idle CPU...")
Signed-off-by: Hui Tang <tanghui20@huawei.com>

parent 2f2eaf1a

kernel/sched/features.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -54,8 +54,8 @@ SCHED_FEAT(TTWU_QUEUE, true)
		/*
		* When doing wakeups, attempt to limit superfluous scans of the LLC domain.
		*/
		SCHED_FEAT(SIS_PROP, false)
		SCHED_FEAT(SIS_UTIL, true)
		SCHED_FEAT(SIS_PROP, true)
		SCHED_FEAT(SIS_UTIL, false)

		#ifdef CONFIG_SCHED_STEAL
		/*