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genirq/affinity: Consider that CPUs on nodes can be unbalanced

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If CPUs on a node are offline at boot time, the number of nodes is
different when building affinity masks for present cpus and when building
affinity masks for possible cpus. This causes the following problem:

In the case that the number of vectors is less than the number of nodes
there are cases where bits of masks for present cpus are overwritten when
building masks for possible cpus.

Fix this by excluding CPUs, which are not part of the current build mask
(present/possible).

[ tglx: Massaged changelog and added comment ]

Fixes: b825921990 ("genirq/affinity: Spread IRQs to all available NUMA nodes")
Signed-off-by: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220331003309.10891-1-yamamoto.rei@jp.fujitsu.com
This commit is contained in:
Rei Yamamoto 2022-03-31 09:33:09 +09:00 committed by Thomas Gleixner
parent 63ef1a8a07
commit 08d835dff9
1 changed files with 3 additions and 2 deletions
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5
kernel/irq/affinity.c
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@ -269,8 +269,9 @@ static int __irq_build_affinity_masks(unsigned int startvec,
*/
if (numvecs <= nodes) {
for_each_node_mask(n, nodemsk) {
cpumask_or(&masks[curvec].mask, &masks[curvec].mask,
node_to_cpumask[n]);
/* Ensure that only CPUs which are in both masks are set */
cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
cpumask_or(&masks[curvec].mask, &masks[curvec].mask, nmsk);
if (++curvec == last_affv)
curvec = firstvec;
}