On Tue, Dec 01, 2020 at 12:33:26PM +0100, Thomas Gleixner wrote:
> On Tue, Dec 01 2020 at 10:20, Peter Zijlstra wrote:
> > On Tue, Dec 01, 2020 at 01:12:25AM +0100, Frederic Weisbecker wrote:
> > Why not something like:
> >
> > void irqtime_account_irq(struct task_struct *curr, unsigned int offset)
> > {
> > struct irqtime *irqtime = this_cpu_ptr(&cpu_irqtime);
> > unsigned int pc = preempt_count() - offset;
> > s64 delta;
> > int cpu;
> >
> > if (!sched_clock_irqtime)
> > return;
> >
> > cpu = smp_processor_id();
> > delta = sched_clock_cpu(cpu) - irqtime->irq_start_time;
> > irqtime->irq_start_time += delta;
> >
> > /*
> > * We do not account for softirq time from ksoftirqd here.
> > * We want to continue accounting softirq time to ksoftirqd thread
> > * in that case, so as not to confuse scheduler with a special task
> > * that do not consume any time, but still wants to run.
> > */
> > if (pc & HARDIRQ_MASK)
> > irqtime_account_delta(irqtime, delta, CPUTIME_IRQ);
> > else if ((pc & SOFTIRQ_OFFSET) && curr != this_cpu_ksoftirqd())
> > irqtime_account_delta(irqtime, delta, CPUTIME_SOFTIRQ);
> > }
>
> Why not making all of this explicit instead of these conditionals?
Hmm, I'm not sure I get what you suggest?
Thanks.
