From 45da7a2b0af8fa29dff2e6ba8926322068350fce Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 18 Aug 2020 10:48:17 +0200 Subject: [PATCH] sched/fair: Exclude the current CPU from find_new_ilb() It is possible for find_new_ilb() to select the current CPU, however, this only happens from newidle balancing, in which case need_resched() will be true, and consequently nohz_csd_func() will not trigger the softirq. Exclude the current CPU from becoming an ILB target. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/fair.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b9368d123451..cd9a37c0601b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -10056,6 +10056,10 @@ static inline int find_new_ilb(void) for_each_cpu_and(ilb, nohz.idle_cpus_mask, housekeeping_cpumask(HK_FLAG_MISC)) { + + if (ilb == smp_processor_id()) + continue; + if (idle_cpu(ilb)) return ilb; }