sched/topology: Fix sched_numa_find_nth_cpu() in non-NUMA case
authorYury Norov <yury.norov@gmail.com>
Sat, 19 Aug 2023 14:12:36 +0000 (07:12 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 20 Nov 2023 10:58:51 +0000 (11:58 +0100)
[ Upstream commit 8ab63d418d4339d996f80d02a00dbce0aa3ff972 ]

When CONFIG_NUMA is enabled, sched_numa_find_nth_cpu() searches for a
CPU in sched_domains_numa_masks. The masks includes only online CPUs,
so effectively offline CPUs are skipped.

When CONFIG_NUMA is disabled, the fallback function should be consistent.

Fixes: cd7f55359c90 ("sched: add sched_numa_find_nth_cpu()")
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20230819141239.287290-5-yury.norov@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
include/linux/topology.h

index fea3237..52f5850 100644 (file)
@@ -251,7 +251,7 @@ extern const struct cpumask *sched_numa_hop_mask(unsigned int node, unsigned int
 #else
 static __always_inline int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node)
 {
-       return cpumask_nth(cpu, cpus);
+       return cpumask_nth_and(cpu, cpus, cpu_online_mask);
 }
 
 static inline const struct cpumask *