From: Wanpeng Li <[email protected]> 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 <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra (Intel) <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Radim <[email protected]> Signed-off-by: Wanpeng Li <[email protected]> --- 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); + + 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); -- 1.9.1
