From: Shrikanth Hegde Date: Mon, 1 Jan 2024 15:46:24 +0000 (+0530) Subject: sched/fair: Add READ_ONCE() and use existing helper function to access ->avg_irq X-Git-Tag: v6.9-rc1~190^2~10 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a6965b31888501f889261a6783f0de6afff84f8d;p=thirdparty%2Fkernel%2Flinux.git sched/fair: Add READ_ONCE() and use existing helper function to access ->avg_irq Use existing helper function cpu_util_irq() instead of open-coding access to ->avg_irq. During review it was noted that ->avg_irq could be updated by a different CPU than the one which is trying to access it. ->avg_irq is updated with WRITE_ONCE(), use READ_ONCE to access it in order to avoid any compiler optimizations. Signed-off-by: Shrikanth Hegde Signed-off-by: Ingo Molnar Reviewed-by: Vincent Guittot Link: https://lore.kernel.org/r/20240101154624.100981-3-sshegde@linux.vnet.ibm.com --- diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 127e727fb7b49..ba3633940f6fc 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9246,10 +9246,8 @@ static inline bool others_have_blocked(struct rq *rq) if (thermal_load_avg(rq)) return true; -#ifdef CONFIG_HAVE_SCHED_AVG_IRQ - if (READ_ONCE(rq->avg_irq.util_avg)) + if (cpu_util_irq(rq)) return true; -#endif return false; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 001fe047bd5d8..d2242679239ec 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3136,7 +3136,7 @@ static inline bool uclamp_rq_is_idle(struct rq *rq) #ifdef CONFIG_HAVE_SCHED_AVG_IRQ static inline unsigned long cpu_util_irq(struct rq *rq) { - return rq->avg_irq.util_avg; + return READ_ONCE(rq->avg_irq.util_avg); } static inline