From b2a02fc43a1f40ef4eb2fb2b06357382608d4d84 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 26 May 2020 18:11:01 +0200 Subject: smp: Optimize send_call_function_single_ipi() Just like the ttwu_queue_remote() IPI, make use of _TIF_POLLING_NRFLAG to avoid sending IPIs to idle CPUs. [ mingo: Fix UP build bug. ] Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200526161907.953304789@infradead.org --- kernel/sched/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel/sched/core.c') diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2cacc1e44a84..fa0d4990618e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2296,6 +2296,16 @@ static void wake_csd_func(void *info) sched_ttwu_pending(); } +void send_call_function_single_ipi(int cpu) +{ + struct rq *rq = cpu_rq(cpu); + + if (!set_nr_if_polling(rq->idle)) + arch_send_call_function_single_ipi(cpu); + else + trace_sched_wake_idle_without_ipi(cpu); +} + /* * Queue a task on the target CPUs wake_list and wake the CPU via IPI if * necessary. The wakee CPU on receipt of the IPI will queue the task -- cgit v1.2.3