On Mon, Dec 28, 2020 at 11:47:48AM +0800, chenshiyan wrote: > From: "shiyan.csy" <shiyan....@alibaba-inc.com> > > exit nohz idle before invoking softirq, or it maymiss > some ticks during softirq. > > Signed-off-by: Shiyan Chen <chenshi...@linux.alibaba.com> > --- > kernel/softirq.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/kernel/softirq.c b/kernel/softirq.c > index 9d71046..59bd6fe 100644 > --- a/kernel/softirq.c > +++ b/kernel/softirq.c > @@ -404,6 +404,10 @@ static inline void tick_irq_exit(void) > if (!in_irq()) > tick_nohz_irq_exit(); > } > + > + /* need to exit nohz idle if there's a softirq */ > + if (in_serving_softirq() || local_softirq_pending()) > + tick_nohz_idle_exit(); > #endif > } > > @@ -416,10 +420,11 @@ static inline void __irq_exit_rcu(void) > #endif > account_hardirq_exit(current); > preempt_count_sub(HARDIRQ_OFFSET); > - if (!in_interrupt() && local_softirq_pending()) > - invoke_softirq(); > > + /* must call before invoke_softirq */ > tick_irq_exit(); > + if (!in_interrupt() && local_softirq_pending()) > + invoke_softirq();
You can't reverse the order here because the softirqs may update the next tick expiry. And that needs to be taken into account by tick_nohz_full_update_tick(). But what issue are you trying to solve exactly? Thanks. > } > > /** > -- > 1.8.3.1 >
