On Tue, Jul 05, 2016 at 12:47:07PM -0400, Rik van Riel wrote: > On Tue, 5 Jul 2016 14:40:34 +0200 > Frederic Weisbecker <fweis...@gmail.com> wrote: > > > ... > > Thanks for the review Frederic. Here is a fixed version of patch 1, > the other three still seem to apply cleanly. > > ---8<--- > > Subject: sched,time: count actually elapsed irq & softirq time > > Currently, if there was any irq or softirq time during 'ticks' > jiffies, the entire period will be accounted as irq or softirq > time. > > This is inaccurate if only a subset of the time was actually spent > handling irqs, and could conceivably mis-count all of the ticks during > a period as irq time, when there was some irq and some softirq time. > > This can actually happen when irqtime_account_process_tick is called > from account_idle_ticks, which can pass a larger number of ticks down > all at once. > > Fix this by changing irqtime_account_hi_update, irqtime_account_si_update, > and steal_account_process_ticks to work with cputime_t time units, and > return the amount of time spent in each mode. > > Rename steal_account_process_ticks to steal_account_process_time, to > reflect that time is now accounted in cputime_t, instead of ticks. > > Additionally, have irqtime_account_process_tick take into account how > much time was spent in each of steal, irq, and softirq time. > > The latter could help improve the accuracy of cputime > accounting when returning from idle on a NO_HZ_IDLE CPU. > > Properly accounting how much time was spent in hardirq and > softirq time will also allow the NO_HZ_FULL code to re-use > these same functions for hardirq and softirq accounting. > > Signed-off-by: Rik van Riel <r...@redhat.com> > --- > include/asm-generic/cputime_nsecs.h | 2 + > kernel/sched/cputime.c | 124 > ++++++++++++++++++++++-------------- > 2 files changed, 79 insertions(+), 47 deletions(-) > > diff --git a/include/asm-generic/cputime_nsecs.h > b/include/asm-generic/cputime_nsecs.h > index 0f1c6f315cdc..918ebb01486c 100644 > --- a/include/asm-generic/cputime_nsecs.h > +++ b/include/asm-generic/cputime_nsecs.h > @@ -50,6 +50,8 @@ typedef u64 __nocast cputime64_t; > (__force u64)(__ct) > #define nsecs_to_cputime(__nsecs) \ > (__force cputime_t)(__nsecs) > +#define nsecs_to_cputime64(__nsecs) \ > + (__force cputime_t)(__nsecs)
(__force cputime64_t) :-) Although functionally that shouldn't matter for cputime_nsecs.h. You probably won't get a warning either. Reviewed-by: Frederic Weisbecker <fweis...@gmail.com> Thanks!
