| Message ID | 1463560115-12962-1-git-send-email-wanpeng.li@hotmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/18/2016 11:28 AM, Wanpeng Li wrote: > From: Wanpeng Li <wanpeng.li@hotmail.com> > > This patch adds steal guest time support to full dynticks CPU > time accounting. After 'commit ff9a9b4c4334 ("sched, time: Switch > VIRT_CPU_ACCOUNTING_GEN to jiffy granularity")', time is jiffy > based sampling even if it's still listened to ring boundaries, so > steal_account_process_tick() is reused to account how much 'ticks' > are steal time after the last accumulation. > > Suggested-by: Rik van Riel <riel@redhat.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Peter Zijlstra (Intel) <peterz@infradead.org> > Cc: Rik van Riel <riel@redhat.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim <rkrcmar@redhat.com> > Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> > --- > v1 -> v2: > * fix divide zero bug, thanks Rik > > kernel/sched/cputime.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c > index 75f98c5..bfa50a0 100644 > --- a/kernel/sched/cputime.c > +++ b/kernel/sched/cputime.c > @@ -257,7 +257,7 @@ void account_idle_time(cputime_t cputime) > cpustat[CPUTIME_IDLE] += (__force u64) cputime; > } > > -static __always_inline bool steal_account_process_tick(void) > +static __always_inline unsigned long steal_account_process_tick(void) > { > #ifdef CONFIG_PARAVIRT > if (static_key_false(¶virt_steal_enabled)) { > @@ -279,7 +279,7 @@ static __always_inline bool steal_account_process_tick(void) > return steal_jiffies; > } > #endif > - return false; > + return 0; > } > > /* > @@ -691,8 +691,12 @@ static cputime_t get_vtime_delta(struct task_struct *tsk) > > static void __vtime_account_system(struct task_struct *tsk) > { > + unsigned long steal_time = steal_account_process_tick(); > cputime_t delta_cpu = get_vtime_delta(tsk); > > + if (steal_time >= delta_cpu) > + return; > + delta_cpu -= steal_time; > account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu)); > } > > @@ -723,7 +727,12 @@ void vtime_account_user(struct task_struct *tsk) > write_seqcount_begin(&tsk->vtime_seqcount); > tsk->vtime_snap_whence = VTIME_SYS; > if (vtime_delta(tsk)) { > + unsigned long steal_time = steal_account_process_tick(); > delta_cpu = get_vtime_delta(tsk); afaik steal_account_process_tick() returns jiffies and get_vtime_delta() cputime, so can't mix them like this : ? > + > + if (steal_time >= delta_cpu) > + return; > + delta_cpu -= steal_time; > account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu)); > } > write_seqcount_end(&tsk->vtime_seqcount); > --Mika -- 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
2016-05-18 17:46 GMT+08:00 Mika Penttilä <mika.penttila@nextfour.com>: > On 05/18/2016 11:28 AM, Wanpeng Li wrote: >> From: Wanpeng Li <wanpeng.li@hotmail.com> >> >> This patch adds steal guest time support to full dynticks CPU >> time accounting. After 'commit ff9a9b4c4334 ("sched, time: Switch >> VIRT_CPU_ACCOUNTING_GEN to jiffy granularity")', time is jiffy >> based sampling even if it's still listened to ring boundaries, so >> steal_account_process_tick() is reused to account how much 'ticks' >> are steal time after the last accumulation. >> >> Suggested-by: Rik van Riel <riel@redhat.com> >> Cc: Ingo Molnar <mingo@kernel.org> >> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> >> Cc: Rik van Riel <riel@redhat.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Frederic Weisbecker <fweisbec@gmail.com> >> Cc: Paolo Bonzini <pbonzini@redhat.com> >> Cc: Radim <rkrcmar@redhat.com> >> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> >> --- >> v1 -> v2: >> * fix divide zero bug, thanks Rik >> >> kernel/sched/cputime.c | 13 +++++++++++-- >> 1 file changed, 11 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c >> index 75f98c5..bfa50a0 100644 >> --- a/kernel/sched/cputime.c >> +++ b/kernel/sched/cputime.c >> @@ -257,7 +257,7 @@ void account_idle_time(cputime_t cputime) >> cpustat[CPUTIME_IDLE] += (__force u64) cputime; >> } >> >> -static __always_inline bool steal_account_process_tick(void) >> +static __always_inline unsigned long steal_account_process_tick(void) >> { >> #ifdef CONFIG_PARAVIRT >> if (static_key_false(¶virt_steal_enabled)) { >> @@ -279,7 +279,7 @@ static __always_inline bool steal_account_process_tick(void) >> return steal_jiffies; >> } >> #endif >> - return false; >> + return 0; >> } >> >> /* >> @@ -691,8 +691,12 @@ static cputime_t get_vtime_delta(struct task_struct *tsk) >> >> static void __vtime_account_system(struct task_struct *tsk) >> { >> + unsigned long steal_time = steal_account_process_tick(); >> cputime_t delta_cpu = get_vtime_delta(tsk); >> >> + if (steal_time >= delta_cpu) >> + return; >> + delta_cpu -= steal_time; >> account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu)); >> } >> >> @@ -723,7 +727,12 @@ void vtime_account_user(struct task_struct *tsk) >> write_seqcount_begin(&tsk->vtime_seqcount); >> tsk->vtime_snap_whence = VTIME_SYS; >> if (vtime_delta(tsk)) { >> + unsigned long steal_time = steal_account_process_tick(); >> delta_cpu = get_vtime_delta(tsk); > > > afaik steal_account_process_tick() returns jiffies and get_vtime_delta() cputime, so can't mix them like this : ? You are right, thanks for your review. I will fix it. Regards, Wanpeng Li -- 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
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 75f98c5..bfa50a0 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -257,7 +257,7 @@ void account_idle_time(cputime_t cputime) cpustat[CPUTIME_IDLE] += (__force u64) cputime; } -static __always_inline bool steal_account_process_tick(void) +static __always_inline unsigned long steal_account_process_tick(void) { #ifdef CONFIG_PARAVIRT if (static_key_false(¶virt_steal_enabled)) { @@ -279,7 +279,7 @@ static __always_inline bool steal_account_process_tick(void) return steal_jiffies; } #endif - return false; + return 0; } /* @@ -691,8 +691,12 @@ static cputime_t get_vtime_delta(struct task_struct *tsk) static void __vtime_account_system(struct task_struct *tsk) { + unsigned long steal_time = steal_account_process_tick(); cputime_t delta_cpu = get_vtime_delta(tsk); + if (steal_time >= delta_cpu) + return; + delta_cpu -= steal_time; account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu)); } @@ -723,7 +727,12 @@ void vtime_account_user(struct task_struct *tsk) write_seqcount_begin(&tsk->vtime_seqcount); tsk->vtime_snap_whence = VTIME_SYS; if (vtime_delta(tsk)) { + unsigned long steal_time = steal_account_process_tick(); delta_cpu = get_vtime_delta(tsk); + + if (steal_time >= delta_cpu) + return; + delta_cpu -= steal_time; account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu)); } write_seqcount_end(&tsk->vtime_seqcount);