Messages in this thread | | | Date | Mon, 6 Jan 2020 16:53:51 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 2/3] sched/cputime: code cleanup in irqtime_account_process_tick |
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On Thu, Jan 02, 2020 at 06:07:53PM +0800, Alex Shi wrote: > In this func, since account_system_time() considers guest time account > and other system time. we could fold the account_guest_time into > account_system_time() to simply the code. > > Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Wanpeng Li <wanpeng.li@hotmail.com> > Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: linux-kernel@vger.kernel.org > --- > kernel/sched/cputime.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c > index cff3e656566d..46b837e94fce 100644 > --- a/kernel/sched/cputime.c > +++ b/kernel/sched/cputime.c > @@ -381,13 +381,10 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, > account_system_index_time(p, cputime, CPUTIME_SOFTIRQ); > } else if (user_tick) { > account_user_time(p, cputime); > - } else if (p == this_rq()->idle) { > + } else if ((p != this_rq()->idle) || (irq_count() != HARDIRQ_OFFSET)) > + account_system_time(p, HARDIRQ_OFFSET, cputime); > + else
I fear we can't really play the exact same game as account_process_tick() here. Since this is irqtime precise accounting, we have already computed the irqtime delta in account_other_time() (or we will at some point in the future) and substracted it from the ticks to account. This means that the remaining cputime to account has to be either utime/stime/gtime/idle-time but not interrupt time, or we may account interrupt time twice. And account_system_time() tries to account irq time, for example if we interrupt a softirq.
Thanks.
> account_idle_time(cputime); > - } else if (p->flags & PF_VCPU) { /* System time or guest time */ > - account_guest_time(p, cputime); > - } else { > - account_system_index_time(p, cputime, CPUTIME_SYSTEM); > - } > } > > static void irqtime_account_idle_ticks(int ticks) > -- > 1.8.3.1 >
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