From 807e5b80687c06715d62df51a5473b231e3e8b15 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Mon, 13 Jun 2016 18:32:46 +0800 Subject: sched/cputime: Add steal time support to full dynticks CPU time accounting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch adds guest steal-time support to full dynticks CPU time accounting. After the following commit: ff9a9b4c4334 ("sched, time: Switch VIRT_CPU_ACCOUNTING_GEN to jiffy granularity") ... time sampling became jiffy based, even if we do the sampling from the context tracking code, so steal_account_process_tick() can be reused to account how many 'ticks' are stolen-time, after the last accumulation. Signed-off-by: Wanpeng Li Signed-off-by: Peter Zijlstra (Intel) Acked-by: Paolo Bonzini Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1465813966-3116-4-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar --- kernel/sched/cputime.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'kernel/sched/cputime.c') diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 75f98c5498d5..3d60e5d76fdb 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(unsigned long max_jiffies) { #ifdef CONFIG_PARAVIRT if (static_key_false(¶virt_steal_enabled)) { @@ -272,14 +272,14 @@ static __always_inline bool steal_account_process_tick(void) * time in jiffies. Lets cast the result to jiffies * granularity and account the rest on the next rounds. */ - steal_jiffies = nsecs_to_jiffies(steal); + steal_jiffies = min(nsecs_to_jiffies(steal), max_jiffies); this_rq()->prev_steal_time += jiffies_to_nsecs(steal_jiffies); account_steal_time(jiffies_to_cputime(steal_jiffies)); return steal_jiffies; } #endif - return false; + return 0; } /* @@ -346,7 +346,7 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, u64 cputime = (__force u64) cputime_one_jiffy; u64 *cpustat = kcpustat_this_cpu->cpustat; - if (steal_account_process_tick()) + if (steal_account_process_tick(ULONG_MAX)) return; cputime *= ticks; @@ -477,7 +477,7 @@ void account_process_tick(struct task_struct *p, int user_tick) return; } - if (steal_account_process_tick()) + if (steal_account_process_tick(ULONG_MAX)) return; if (user_tick) @@ -681,12 +681,14 @@ static cputime_t vtime_delta(struct task_struct *tsk) static cputime_t get_vtime_delta(struct task_struct *tsk) { unsigned long now = READ_ONCE(jiffies); - unsigned long delta = now - tsk->vtime_snap; + unsigned long delta_jiffies, steal_jiffies; + delta_jiffies = now - tsk->vtime_snap; + steal_jiffies = steal_account_process_tick(delta_jiffies); WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_INACTIVE); tsk->vtime_snap = now; - return jiffies_to_cputime(delta); + return jiffies_to_cputime(delta_jiffies - steal_jiffies); } static void __vtime_account_system(struct task_struct *tsk) -- cgit