[PATCH 27/33] kthread: Rely on HK_TYPE_DOMAIN for preferred affinity management
From: Frederic Weisbecker <frederic@kernel.org>
Date: 2026-01-01 22:17:54
Also in:
cgroups, linux-arm-kernel, linux-block, linux-mm, linux-pci, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Unbound kthreads want to run neither on nohz_full CPUs nor on domain isolated CPUs. And since nohz_full implies domain isolation, checking the latter is enough to verify both. Therefore exclude kthreads from domain isolation. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> --- kernel/kthread.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 85ccf5bb17c9..968fa5868d21 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c@@ -362,18 +362,20 @@ static void kthread_fetch_affinity(struct kthread *kthread, struct cpumask *cpum { const struct cpumask *pref; + guard(rcu)(); + if (kthread->preferred_affinity) { pref = kthread->preferred_affinity; } else { if (kthread->node == NUMA_NO_NODE) - pref = housekeeping_cpumask(HK_TYPE_KTHREAD); + pref = housekeeping_cpumask(HK_TYPE_DOMAIN); else pref = cpumask_of_node(kthread->node); } - cpumask_and(cpumask, pref, housekeeping_cpumask(HK_TYPE_KTHREAD)); + cpumask_and(cpumask, pref, housekeeping_cpumask(HK_TYPE_DOMAIN)); if (cpumask_empty(cpumask)) - cpumask_copy(cpumask, housekeeping_cpumask(HK_TYPE_KTHREAD)); + cpumask_copy(cpumask, housekeeping_cpumask(HK_TYPE_DOMAIN)); } static void kthread_affine_node(void)
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2.51.1