From: Frederic Weisbecker <frederic@kernel.org>
Date: Tue, 3 Jun 2025 19:15:32 +0000 (+0200)
Subject: sched: Switch the fallback task allowed cpumask to HK_TYPE_DOMAIN
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf5b0c27fad2626789624deea10f43da499ad740;p=thirdparty%2Flinux.git

sched: Switch the fallback task allowed cpumask to HK_TYPE_DOMAIN

Tasks that have all their allowed CPUs offline don't want their affinity
to fallback on either nohz_full CPUs or on domain isolated CPUs. And
since nohz_full implies domain isolation, checking the latter is enough
to verify both.

Therefore exclude domain isolation from fallback task affinity.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Waiman Long <longman@redhat.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: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
---

diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h
index ac01dc4eb2cec..ed3dd0f3fe194 100644
--- a/include/linux/mmu_context.h
+++ b/include/linux/mmu_context.h
@@ -24,7 +24,7 @@ static inline void leave_mm(void) { }
 #ifndef task_cpu_possible_mask
 # define task_cpu_possible_mask(p)	cpu_possible_mask
 # define task_cpu_possible(cpu, p)	true
-# define task_cpu_fallback_mask(p)	housekeeping_cpumask(HK_TYPE_TICK)
+# define task_cpu_fallback_mask(p)	housekeeping_cpumask(HK_TYPE_DOMAIN)
 #else
 # define task_cpu_possible(cpu, p)	cpumask_test_cpu((cpu), task_cpu_possible_mask(p))
 #endif