cgroups: add cpu_relax() calls in css_tryget() and cgroup_clear_css_refs()

css_tryget() and cgroup_clear_css_refs() contain polling loops; these
loops should have cpu_relax calls in them to reduce cross-cache traffic.

Signed-off-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Paul Menage
2009-01-29 14:25:21 -08:00
committed by Linus Torvalds
parent 1404f06565
commit 804b3c28a4
2 changed files with 6 additions and 2 deletions

View File

@@ -99,6 +99,7 @@ static inline bool css_tryget(struct cgroup_subsys_state *css)
while (!atomic_inc_not_zero(&css->refcnt)) {
if (test_bit(CSS_REMOVED, &css->flags))
return false;
cpu_relax();
}
return true;
}