From c1837918595ad4a81b58e9b030a47544c88ed41f Mon Sep 17 00:00:00 2001 From: Rei Yamamoto Date: Thu, 31 Mar 2022 09:33:09 +0900 Subject: [PATCH] genirq/affinity: Consider that CPUs on nodes can be unbalanced 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: 0a0bb829f4be ("genirq/affinity: Spread IRQs to all available NUMA nodes") Signed-off-by: Rei Yamamoto Signed-off-by: Thomas Gleixner Reviewed-by: Ming Lei Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220331003309.10891-1-yamamoto.rei@jp.fujitsu.com --- kernel/irq/affinity.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index f7ff8919dc9bb..fdf170404650f 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -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; } -- 2.39.5