tree ea4f847f2a29face1b5774c6d44ec41bf92e302b
parent cf417141cbb3a4ceb5cca15b2c1f099bd0a6603c
author Max Krasnyansky <maxk@qualcomm.com> 1220040701 -0700
committer Ingo Molnar <mingo@elte.hu> 1220721735 +0200

sched: arch_reinit_sched_domains() must destroy domains to force rebuild

What I realized recently is that calling rebuild_sched_domains() in
arch_reinit_sched_domains() by itself is not enough when cpusets are enabled.
partition_sched_domains() code is trying to avoid unnecessary domain rebuilds
and will not actually rebuild anything if new domain masks match the old ones.

What this means is that doing
     echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
on a system with cpusets enabled will not take affect untill something changes
in the cpuset setup (ie new sets created or deleted).

This patch fixes restore correct behaviour where domains must be rebuilt in
order to enable MC powersaving flags.

Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS.
Also tested on dual-core Core2 laptop. Lockdep is happy and things are working
as expected.

Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>