Messages in this thread | | | Subject | Re: [PATCH 2/6] Add IRQ_TIME_ACCOUNTING, finer accounting of CPU irq time | From | Peter Zijlstra <> | Date | Sun, 19 Sep 2010 13:11:48 +0200 |
| |
On Thu, 2010-09-16 at 18:56 -0700, Venkatesh Pallipadi wrote: > > Signed-off-by: Venkatesh Pallipadi <venki@google.com> > --- > include/linux/hardirq.h | 2 +- > include/linux/sched.h | 11 +++++++++++ > kernel/sched.c | 38 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 50 insertions(+), 1 deletions(-) > > diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h > index ce22d09..bfafd29 100644 > --- a/include/linux/hardirq.h > +++ b/include/linux/hardirq.h > @@ -132,7 +132,7 @@ extern void synchronize_irq(unsigned int irq); > > struct task_struct; > > -#ifndef CONFIG_VIRT_CPU_ACCOUNTING > +#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING) > static inline void account_system_vtime(struct task_struct *tsk) > { > } > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 1e2a6db..dbb6808 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1826,6 +1826,17 @@ extern void sched_clock_idle_sleep_event(void); > extern void sched_clock_idle_wakeup_event(u64 delta_ns); > #endif > > +#ifdef CONFIG_IRQ_TIME_ACCOUNTING > +/* > + * An i/f to runtime opt-in for irq time accounting based off of sched_clock. > + * The reason for this explicit opt-in is not to have perf penalty with > + * slow sched_clocks. > + */ > +extern void enable_sched_clock_irqtime(void); > +#else > +static inline void enable_sched_clock_irqtime(void) {} > +#endif > + > extern unsigned long long > task_sched_runtime(struct task_struct *task); > extern unsigned long long thread_group_sched_runtime(struct task_struct *task); > diff --git a/kernel/sched.c b/kernel/sched.c > index ed09d4f..912d2de 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -1917,6 +1917,44 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) > dec_nr_running(rq); > } > > +#ifdef CONFIG_IRQ_TIME_ACCOUNTING > + > +static DEFINE_PER_CPU(u64, cpu_hardirq_time); > +static DEFINE_PER_CPU(u64, cpu_softirq_time); > + > +static DEFINE_PER_CPU(u64, irq_start_time); > +static int sched_clock_irqtime; > + > +void enable_sched_clock_irqtime(void) > +{ > + sched_clock_irqtime = 1; > +} > + > +void account_system_vtime(struct task_struct *tsk) > +{ > + unsigned long flags; > + int cpu; > + u64 now, delta; > + > + if (!sched_clock_irqtime) > + return; > + > + local_irq_save(flags); > + > + cpu = task_cpu(tsk);
Can this ever be anything other can smp_processor_id() and current?
> + now = sched_clock();
this should be using one of the kernel/sched_clock.c thingies, probably local_clock(), or sched_clock_cpu(cpu).
> + delta = now - per_cpu(irq_start_time, cpu); > + per_cpu(irq_start_time, cpu) = now; > + if (hardirq_count()) > + per_cpu(cpu_hardirq_time, cpu) += delta; > + else if (softirq_count()) > + per_cpu(cpu_softirq_time, cpu) += delta; > + > + local_irq_restore(flags); > +}
Also, this isn't a complete API, its very asymmetric, please cure that.
| |