From 3dc6f6c8efe2d9148865664fffbe9dd89fb0d157 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 8 Mar 2024 11:58:59 +0100 Subject: [PATCH] sched/balancing: Update run_rebalance_domains() comments The first sentence of the comment explaining run_rebalance_domains() is historic and not true anymore: * run_rebalance_domains is triggered when needed from the scheduler tick. ... contradicted/modified by the second sentence: * Also triggered for NOHZ idle balancing (with NOHZ_BALANCE_KICK set). Avoid that kind of confusion straight away and explain from what places sched_balance_softirq() is triggered. Signed-off-by: Ingo Molnar Reviewed-by: Vincent Guittot Acked-by: Valentin Schneider Link: https://lore.kernel.org/r/20240308105901.1096078-9-mingo@kernel.org --- kernel/sched/fair.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f3c03c6db3c85..b567c0790f444 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12409,9 +12409,12 @@ out: } /* - * This softirq may be triggered from the scheduler tick, or by - * any of the flags in NOHZ_KICK_MASK: NOHZ_BALANCE_KICK, - * NOHZ_STATS_KICK or NOHZ_NEXT_KICK. + * This softirq handler is triggered via SCHED_SOFTIRQ from two places: + * + * - directly from the local scheduler_tick() for periodic load balancing + * + * - indirectly from a remote scheduler_tick() for NOHZ idle balancing + * through the SMP cross-call nohz_csd_func() */ static __latent_entropy void run_rebalance_domains(struct softirq_action *h) { -- 2.30.2