Messages in this thread | | | Subject | Re: [PATCH 5/6] Export ns irqtimes through /proc/stat -v1 | From | Peter Zijlstra <> | Date | Tue, 26 Oct 2010 11:45:50 +0200 |
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On Mon, 2010-10-25 at 15:30 -0700, Venkatesh Pallipadi wrote: > +static void irqtime_account_process_tick(struct task_struct *p, int user_tick, > + struct rq *rq) > +{ > + cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); > + cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy); > + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; > + > + if (irqtime_account_hi_update()) { > + cpustat->irq = cputime64_add(cpustat->irq, tmp); > + } else if (irqtime_account_si_update()) { > + cpustat->softirq = cputime64_add(cpustat->softirq, tmp); > + } else
I'm still not sure about this else stmt, the above two conditions can basically 'eat' user/system ticks. What we need to show is that there is no bias towards either kind so the ratio is not affected -- can we make such an argument?
> if (user_tick) { > + account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); > + } else if (p == rq->idle) { > + account_idle_time(cputime_one_jiffy); > + } else if (p->flags & PF_VCPU) { /* System time or guest time */ > + account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled); > + } else { > + __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, > + &cpustat->system); > + } > +}
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