Hi, I'm a bit confused with the changelog, let's try to clarify:
On Mon, Feb 01, 2021 at 11:45:43AM +0800, chenshiyan wrote: > When the cpu is continuously idle, tick_irq_exit() will count next tick > expiry What do you mean by counting next tick expiry here? Is is when tick_nohz_full_update_tick() reprogramms the next tick? > with maybe several periodic ticks you mean that perhaps it's not going to stop it right now? > but if it enters softirq before next tick Not sure what you mean here. > invoke_softirq() is called before tick_irq_exit(), > there will be no ticks during softirq. Ok the issue happens when an IRQ fires while the tick is stopped, right? > So with sched_clock_irqtime > closing, sirq is very low in nohz idle even if the softirq costs much > time beause of the sampling ticks missing(sirq will be much higher and > seem exact if the cpu is busy). But this only happens when sched_clock() is based on jiffies, right? Are you working on an architecture that doesn't implement it? Thanks. > > Signed-off-by: chenshiyan <[email protected]> > --- > kernel/softirq.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/softirq.c b/kernel/softirq.c > index 9d71046..8f3f71b9 100644 > --- a/kernel/softirq.c > +++ b/kernel/softirq.c > @@ -210,6 +210,7 @@ static inline void invoke_softirq(void) > return; > > if (!force_irqthreads) { > + tick_nohz_idle_restart_tick(); > #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK > /* > * We can safely execute softirq on the current stack if > -- > 1.8.3.1 >
