Commit 890a5409 authored Feb 09, 2015 by Jan Beulich Committed by Ingo Molnar Feb 18, 2015

sched/numa: Avoid some pointless iterations



Commit 81907478 ("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>

parent 095bebf6

kernel/sched/fair.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1774,6 +1774,8 @@ static int preferred_group_nid(struct task_struct *p, int nid)
	}		}
	}		}
	/* Next round, evaluate the nodes within max_group. */		/* Next round, evaluate the nodes within max_group. */
			if (!max_faults)
			break;
	nodes = max_group;		nodes = max_group;
	}		}
	return nid;		return nid;