lkml.org 
[lkml]   [2017]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:irq/urgent] irq/affinity: Fix extra vecs calculation
Commit-ID:  3412386b531244f24a27c79ee003506a52a00848
Gitweb: http://git.kernel.org/tip/3412386b531244f24a27c79ee003506a52a00848
Author: Keith Busch <keith.busch@intel.com>
AuthorDate: Thu, 13 Apr 2017 13:28:12 -0400
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 13 Apr 2017 23:41:00 +0200

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: 7bf8222b9bd0 ("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>

---
kernel/irq/affinity.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index dc52911..d052947 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -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++) {
\
 
 \ /
  Last update: 2017-04-13 23:47    [W:0.668 / U:1.828 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site