sched: Pre-compute cpumask_weight(sched_domain_span(sd))
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Fri, 16 Apr 2010 12:59:29 +0000 (14:59 +0200)
committerIngo Molnar <mingo@elte.hu>
Fri, 23 Apr 2010 09:02:02 +0000 (11:02 +0200)
commit669c55e9f99b90e46eaa0f98a67ec53d46dc969a
tree9f60bcf779e5ec786c05b8053b59e091edcb418c
parent74f5187ac873042f502227701ed1727e7c5fbfa9
sched: Pre-compute cpumask_weight(sched_domain_span(sd))

Dave reported that his large SPARC machines spend lots of time in
hweight64(), try and optimize some of those needless cpumask_weight()
invocations (esp. with the large offstack cpumasks these are very
expensive indeed).

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
include/linux/sched.h
kernel/sched.c
kernel/sched_fair.c