]> git.ipfire.org Git - thirdparty/linux.git/commit
sched/arm64: Move fallback task cpumask to HK_TYPE_DOMAIN
authorFrederic Weisbecker <frederic@kernel.org>
Thu, 24 Jul 2025 21:38:48 +0000 (23:38 +0200)
committerFrederic Weisbecker <frederic@kernel.org>
Tue, 3 Feb 2026 14:23:35 +0000 (15:23 +0100)
commit79c0abaf06fca6e715cf792daed580542fc4a2c4
tree2e94c7702c24f509b64699d352ea3d87750cab81
parentbf5b0c27fad2626789624deea10f43da499ad740
sched/arm64: Move fallback task cpumask to HK_TYPE_DOMAIN

When none of the allowed CPUs of a task are online, it gets migrated
to the fallback cpumask which is all the non nohz_full CPUs.

However just like nohz_full CPUs, domain isolated CPUs don't want to be
disturbed by tasks that have lost their CPU affinities.

And since nohz_full rely on domain isolation to work correctly, the
housekeeping mask of domain isolated CPUs should always be a subset of
the housekeeping mask of nohz_full CPUs (there can be CPUs that are
domain isolated but not nohz_full, OTOH there shouldn't be nohz_full
CPUs that are not domain isolated):

HK_TYPE_DOMAIN & HK_TYPE_KERNEL_NOISE == HK_TYPE_DOMAIN

Therefore use HK_TYPE_DOMAIN as the appropriate fallback target for
tasks. Note that cpuset isolated partitions are not supported on those
systems and may result in undefined behaviour.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Documentation/arch/arm64/asymmetric-32bit.rst
arch/arm64/kernel/cpufeature.c