From 8537bb95a63e4be330359721f0ecd422f4a4c0ca Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 7 Dec 2015 16:55:23 +0100 Subject: [PATCH] nohz: Implement wide kick on top of irq work It simplifies it and allows wide kick to be performed, even when IRQs are disabled, without an asynchronous level in the middle. This comes at a cost of some more overhead on features like perf and posix cpu timers slow-paths, which is probably not much important for nohz full users. Requested-by: Peter Zijlstra Reviewed-by: Chris Metcalf Cc: Christoph Lameter Cc: Chris Metcalf Cc: Ingo Molnar Cc: Luiz Capitulino Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Signed-off-by: Frederic Weisbecker --- kernel/time/tick-sched.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 0b17424349eb..548a4e2551a9 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -234,24 +234,20 @@ void tick_nohz_full_kick_cpu(int cpu) irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu); } -static void nohz_full_kick_ipi(void *info) -{ - /* Empty, the tick restart happens on tick_nohz_irq_exit() */ -} - /* * Kick all full dynticks CPUs in order to force these to re-evaluate * their dependency on the tick and restart it if necessary. */ void tick_nohz_full_kick_all(void) { + int cpu; + if (!tick_nohz_full_running) return; preempt_disable(); - smp_call_function_many(tick_nohz_full_mask, - nohz_full_kick_ipi, NULL, false); - tick_nohz_full_kick(); + for_each_cpu_and(cpu, tick_nohz_full_mask, cpu_online_mask) + tick_nohz_full_kick_cpu(cpu); preempt_enable(); }