From 1c3329df409b9b50517bf4a1399ed793d277a20c Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 2 Jun 2025 12:32:32 +0200 Subject: [PATCH] sched/isolation: Remove HK_TYPE_TICK test from cpu_is_isolated() It doesn't make sense to use nohz_full without also isolating the related CPUs from the domain topology, either through the use of isolcpus= or cpuset isolated partitions. And now HK_TYPE_DOMAIN includes all kinds of domain isolated CPUs. This means that HK_TYPE_DOMAIN should always be a subset of HK_TYPE_KERNEL_NOISE (of which HK_TYPE_TICK is only an alias). Therefore if a CPU is not HK_TYPE_DOMAIN, it shouldn't be HK_TYPE_KERNEL_NOISE either. Testing the former is then enough. Simplify cpu_is_isolated() accordingly. Signed-off-by: Frederic Weisbecker Acked-by: Waiman Long Cc: Ingo Molnar Cc: Marco Crivellari Cc: Michal Hocko Cc: Peter Zijlstra Cc: Tejun Heo Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Waiman Long --- include/linux/sched/isolation.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h index d0fb0f6473186..dc3975ff1b2e1 100644 --- a/include/linux/sched/isolation.h +++ b/include/linux/sched/isolation.h @@ -82,8 +82,7 @@ static inline bool housekeeping_cpu(int cpu, enum hk_type type) static inline bool cpu_is_isolated(int cpu) { - return !housekeeping_test_cpu(cpu, HK_TYPE_DOMAIN) || - !housekeeping_test_cpu(cpu, HK_TYPE_TICK); + return !housekeeping_test_cpu(cpu, HK_TYPE_DOMAIN); } #endif /* _LINUX_SCHED_ISOLATION_H */ -- 2.47.3