Messages in this thread | | | Date | Mon, 20 Sep 2010 10:13:23 -0700 | Subject | Re: [PATCH 2/6] Add IRQ_TIME_ACCOUNTING, finer accounting of CPU irq time | From | Venkatesh Pallipadi <> |
| |
On Sun, Sep 19, 2010 at 4:11 AM, Peter Zijlstra <peterz@infradead.org> wrote: > 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).
I don't really need task there. I can use smp_processor_id() or task_cpu(tsk) and I think latter one would be cheaper.
You mean sched_clock() is not the right interface to use here. sched_clock_cpu() uses either sched_clock or remote_cpu stuff which I don't really need here and local_clock() also has irq disable/smp_processor_id() and calls sched_clock_cpu in turn. sched_clock() seemed to be more appropriate.
Thanks, Venki -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |