Commit 3412386b authored Apr 13, 2017 by Keith Busch Committed by Thomas Gleixner Apr 13, 2017

irq/affinity: Fix extra vecs calculation



This fixes a math error calculating the extra_vecs. The error assumed
only 1 cpu per vector, but the value needs to account for the actual
number of cpus per vector in order to get the correct remainder for
extra CPU assignment.

Fixes: 7bf8222b ("irq/affinity: Fix CPU spread for unbalanced nodes")
Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Link: http://lkml.kernel.org/r/1492104492-19943-1-git-send-email-keith.busch@intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 7bf8222b

kernel/irq/affinity.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -108,7 +108,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
		vecs_to_assign = min(vecs_per_node, ncpus);

		/* Account for rounding errors */
		extra_vecs = ncpus - vecs_to_assign;
		extra_vecs = ncpus - vecs_to_assign * (ncpus / vecs_to_assign);

		for (v = 0; curvec < last_affv && v < vecs_to_assign;
		curvec++, v++) {

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