Re: [PATCH v4 7/9] KVM-GST: KVM Steal time accounting

From: Peter Zijlstra
Date: Sat Jul 02 2011 - 06:32:04 EST


On Fri, 2011-07-01 at 17:22 -0400, Glauber Costa wrote:
> @@ -3929,6 +3945,23 @@ void account_process_tick(struct task_struct *p, int user_tick)
> return;
> }
>
> +#ifdef CONFIG_PARAVIRT
> + if (static_branch(&paravirt_steal_enabled)) {
> + u64 steal, st = 0;
> +
> + steal = paravirt_steal_clock(smp_processor_id());
> + steal -= this_rq()->prev_steal_time;
> +
> + st = steal_ticks(steal);
> + this_rq()->prev_steal_time += st * TICK_NSEC;
> +
> + if (st) {
> + account_steal_time(st);
> + return;
> + }
> + }
> +#endif
> +
> if (user_tick)
> account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
> else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))

So I was about to send an Ack for this patch, when I noticed that this
will all be dead code when CONFIG_IRQ_TIME_ACCOUNTING &&
sched_clock_irqtime.

I think irqtime_account_process_tick() wants a similar hunk (which
suggests splitting it out into an inline function).
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