Messages in this thread Patch in this message | | | Date | Wed, 18 Feb 2015 09:10:29 -0800 | From | tip-bot for Jan Beulich <> | Subject | [tip:sched/core] sched/numa: Avoid some pointless iterations |
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Commit-ID: 890a5409f9d0c84d75a1e16eebdfe91d8a57ef1e Gitweb: http://git.kernel.org/tip/890a5409f9d0c84d75a1e16eebdfe91d8a57ef1e Author: Jan Beulich <JBeulich@suse.com> AuthorDate: Mon, 9 Feb 2015 12:30:00 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Wed, 18 Feb 2015 16:18:02 +0100
sched/numa: Avoid some pointless iterations
Commit 81907478c431 ("sched/fair: Avoid using uninitialized variable in preferred_group_nid()") unconditionally initializes max_group with NODE_MASK_NONE, this means that when !max_faults (max_group didn't get set), we'll now continue the iteration with an empty mask.
Which in turn makes the actual body of the loop go away, so we'll just iterate until completion; short circuit this by breaking out of the loop as soon as this would happen.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150209113727.GS5029@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/sched/fair.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 28cbaca..ee595ef 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1774,6 +1774,8 @@ static int preferred_group_nid(struct task_struct *p, int nid) } } /* Next round, evaluate the nodes within max_group. */ + if (!max_faults) + break; nodes = max_group; } return nid;
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