Commit 32a8df4e authored Dec 19, 2014 by Yuyang Du Committed by Ingo Molnar Jan 09, 2015

sched: Fix odd values in effective_load() calculations



In effective_load, we have (long w * unsigned long tg->shares) / long W,
when w is negative, it is cast to unsigned long and hence the product is
insanely large. Fix this by casting tg->shares to long.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20141219002956.GA25405@intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 536ebe9c

kernel/sched/fair.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -4424,7 +4424,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
		* wl = S * s'_i; see (2)
		*/
		if (W > 0 && w < W)
		wl = (w * tg->shares) / W;
		wl = (w * (long)tg->shares) / W;
		else
		wl = tg->shares;

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