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?
Thanks,
tglx
