sched: Pre-compute cpumask_weight(sched_domain_span(sd))
commit6efd9bbce0d4b02d295f28054caa74e6edf811b7
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Fri, 16 Apr 2010 12:59:29 +0000 (16 14:59 +0200)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 20 Sep 2010 20:18:11 +0000 (20 13:18 -0700)
tree8b10422793dacadd0b91a40af1c601d3080a1bf3
parentac8f51da79873b84461e77ee2b19d02a253add3e
sched: Pre-compute cpumask_weight(sched_domain_span(sd))

commit 669c55e9f99b90e46eaa0f98a67ec53d46dc969a upstream

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>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
include/linux/sched.h
kernel/sched.c
kernel/sched_fair.c