| Message ID | 1309793548-16714-8-git-send-email-glommer@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 2011-07-04 at 11:32 -0400, Glauber Costa wrote: > This patch accounts steal time time in account_process_tick. > If one or more tick is considered stolen in the current > accounting cycle, user/system accounting is skipped. Idle is fine, > since the hypervisor does not report steal time if the guest > is halted. > > Accounting steal time from the core scheduler give us the > advantage of direct acess to the runqueue data. In a later > opportunity, it can be used to tweak cpu power and make > the scheduler aware of the time it lost. > > Signed-off-by: Glauber Costa <glommer@redhat.com> > CC: Rik van Riel <riel@redhat.com> > CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Venki, can you have a look at that irqtime_account_process_tick(), I think adding the steal time up front like this is fine, because it suffers from the same 'problem' as both irqtime thingies. > CC: Avi Kivity <avi@redhat.com> > CC: Anthony Liguori <aliguori@us.ibm.com> > CC: Eric B Munson <emunson@mgebm.net> > --- > kernel/sched.c | 41 +++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 41 insertions(+), 0 deletions(-) > > diff --git a/kernel/sched.c b/kernel/sched.c > index 3f2e502..aa6c030 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -75,6 +75,7 @@ > #include <asm/tlb.h> > #include <asm/irq_regs.h> > #include <asm/mutex.h> > +#include <asm/paravirt.h> > > #include "sched_cpupri.h" > #include "workqueue_sched.h" > @@ -528,6 +529,9 @@ struct rq { > #ifdef CONFIG_IRQ_TIME_ACCOUNTING > u64 prev_irq_time; > #endif > +#ifdef CONFIG_PARAVIRT > + u64 prev_steal_time; > +#endif > > /* calc_load related fields */ > unsigned long calc_load_update; > @@ -1953,6 +1957,18 @@ void account_system_vtime(struct task_struct *curr) > } > EXPORT_SYMBOL_GPL(account_system_vtime); > > +#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ > + > +#ifdef CONFIG_PARAVIRT > +static inline u64 steal_ticks(u64 steal) > +{ > + if (unlikely(steal > NSEC_PER_SEC)) > + return div_u64(steal, TICK_NSEC); > + > + return __iter_div_u64_rem(steal, TICK_NSEC, &steal); > +} > +#endif > + > static void update_rq_clock_task(struct rq *rq, s64 delta) > { > s64 irq_delta; > @@ -3845,6 +3861,25 @@ void account_idle_time(cputime_t cputime) > cpustat->idle = cputime64_add(cpustat->idle, cputime64); > } > > +static __always_inline bool steal_account_process_tick(void) > +{ > +#ifdef CONFIG_PARAVIRT > + if (static_branch(¶virt_steal_enabled)) { > + u64 steal, st = 0; > + > + steal = paravirt_steal_clock(smp_processor_id()); > + steal -= this_rq()->prev_steal_time; > + > + st = steal_ticks(steal); > + this_rq()->prev_steal_time += st * TICK_NSEC; > + > + account_steal_time(st); > + return st; > + } > +#endif > + return false; > +} > + > #ifndef CONFIG_VIRT_CPU_ACCOUNTING > > #ifdef CONFIG_IRQ_TIME_ACCOUNTING > @@ -3876,6 +3911,9 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, > cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy); > struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; > > + if (steal_account_process_tick()) > + return; > + > if (irqtime_account_hi_update()) { > cpustat->irq = cputime64_add(cpustat->irq, tmp); > } else if (irqtime_account_si_update()) { > @@ -3929,6 +3967,9 @@ void account_process_tick(struct task_struct *p, int user_tick) > return; > } > > + if (steal_account_process_tick()) > + return; > + > if (user_tick) > account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); > else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 04 Jul 2011, Glauber Costa wrote: > This patch accounts steal time time in account_process_tick. > If one or more tick is considered stolen in the current > accounting cycle, user/system accounting is skipped. Idle is fine, > since the hypervisor does not report steal time if the guest > is halted. > > Accounting steal time from the core scheduler give us the > advantage of direct acess to the runqueue data. In a later > opportunity, it can be used to tweak cpu power and make > the scheduler aware of the time it lost. > > Signed-off-by: Glauber Costa <glommer@redhat.com> > CC: Rik van Riel <riel@redhat.com> > CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> > CC: Peter Zijlstra <peterz@infradead.org> > CC: Avi Kivity <avi@redhat.com> > CC: Anthony Liguori <aliguori@us.ibm.com> > CC: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net>
On 07/04/2011 11:32 AM, Glauber Costa wrote: > This patch accounts steal time time in account_process_tick. > If one or more tick is considered stolen in the current > accounting cycle, user/system accounting is skipped. Idle is fine, > since the hypervisor does not report steal time if the guest > is halted. > > Accounting steal time from the core scheduler give us the > advantage of direct acess to the runqueue data. In a later > opportunity, it can be used to tweak cpu power and make > the scheduler aware of the time it lost. > > Signed-off-by: Glauber Costa<glommer@redhat.com> > CC: Rik van Riel<riel@redhat.com> > CC: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com> > CC: Peter Zijlstra<peterz@infradead.org> > CC: Avi Kivity<avi@redhat.com> > CC: Anthony Liguori<aliguori@us.ibm.com> > CC: Eric B Munson<emunson@mgebm.net> Acked-by: Rik van Riel <riel@redhat.com>
diff --git a/kernel/sched.c b/kernel/sched.c index 3f2e502..aa6c030 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -75,6 +75,7 @@ #include <asm/tlb.h> #include <asm/irq_regs.h> #include <asm/mutex.h> +#include <asm/paravirt.h> #include "sched_cpupri.h" #include "workqueue_sched.h" @@ -528,6 +529,9 @@ struct rq { #ifdef CONFIG_IRQ_TIME_ACCOUNTING u64 prev_irq_time; #endif +#ifdef CONFIG_PARAVIRT + u64 prev_steal_time; +#endif /* calc_load related fields */ unsigned long calc_load_update; @@ -1953,6 +1957,18 @@ void account_system_vtime(struct task_struct *curr) } EXPORT_SYMBOL_GPL(account_system_vtime); +#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ + +#ifdef CONFIG_PARAVIRT +static inline u64 steal_ticks(u64 steal) +{ + if (unlikely(steal > NSEC_PER_SEC)) + return div_u64(steal, TICK_NSEC); + + return __iter_div_u64_rem(steal, TICK_NSEC, &steal); +} +#endif + static void update_rq_clock_task(struct rq *rq, s64 delta) { s64 irq_delta; @@ -3845,6 +3861,25 @@ void account_idle_time(cputime_t cputime) cpustat->idle = cputime64_add(cpustat->idle, cputime64); } +static __always_inline bool steal_account_process_tick(void) +{ +#ifdef CONFIG_PARAVIRT + if (static_branch(¶virt_steal_enabled)) { + u64 steal, st = 0; + + steal = paravirt_steal_clock(smp_processor_id()); + steal -= this_rq()->prev_steal_time; + + st = steal_ticks(steal); + this_rq()->prev_steal_time += st * TICK_NSEC; + + account_steal_time(st); + return st; + } +#endif + return false; +} + #ifndef CONFIG_VIRT_CPU_ACCOUNTING #ifdef CONFIG_IRQ_TIME_ACCOUNTING @@ -3876,6 +3911,9 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy); struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + if (steal_account_process_tick()) + return; + if (irqtime_account_hi_update()) { cpustat->irq = cputime64_add(cpustat->irq, tmp); } else if (irqtime_account_si_update()) { @@ -3929,6 +3967,9 @@ void account_process_tick(struct task_struct *p, int user_tick) return; } + if (steal_account_process_tick()) + return; + if (user_tick) account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. Signed-off-by: Glauber Costa <glommer@redhat.com> CC: Rik van Riel <riel@redhat.com> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Peter Zijlstra <peterz@infradead.org> CC: Avi Kivity <avi@redhat.com> CC: Anthony Liguori <aliguori@us.ibm.com> CC: Eric B Munson <emunson@mgebm.net> --- kernel/sched.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 files changed, 41 insertions(+), 0 deletions(-)