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>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e3e900f..dfea405 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -960,6 +960,7 @@
char *name;
#endif
+ unsigned int span_weight;
/*
* Span of all CPUs in this domain.
*
