From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753137AbcERM2E (ORCPT ); Wed, 18 May 2016 08:28:04 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:36379 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751911AbcERM2C (ORCPT ); Wed, 18 May 2016 08:28:02 -0400 From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Wanpeng Li , Ingo Molnar , "Peter Zijlstra (Intel)" , Rik van Riel , Thomas Gleixner , Frederic Weisbecker , Paolo Bonzini , Radim Subject: [PATCH v3] sched/cputime: add steal time support to full dynticks CPU time accounting Date: Wed, 18 May 2016 20:27:34 +0800 Message-Id: <1463574454-3587-1-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li 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 Cc: Ingo Molnar Cc: Peter Zijlstra (Intel) Cc: Rik van Riel Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: Paolo Bonzini Cc: Radim Signed-off-by: Wanpeng Li --- v2 -> v3: * convert steal time jiffies to cputime v1 -> v2: * fix divide zero bug, thanks Rik kernel/sched/cputime.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 75f98c5..f51c98c 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 +691,14 @@ static cputime_t get_vtime_delta(struct task_struct *tsk) static void __vtime_account_system(struct task_struct *tsk) { + cputime_t steal_time; cputime_t delta_cpu = get_vtime_delta(tsk); + unsigned long delta_st = steal_account_process_tick(); + steal_time = jiffies_to_cputime(delta_st); + 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 +729,16 @@ void vtime_account_user(struct task_struct *tsk) write_seqcount_begin(&tsk->vtime_seqcount); tsk->vtime_snap_whence = VTIME_SYS; if (vtime_delta(tsk)) { + cputime_t steal_time; + unsigned long delta_st = steal_account_process_tick(); delta_cpu = get_vtime_delta(tsk); + steal_time = jiffies_to_cputime(delta_st); + + if (steal_time >= delta_cpu) { + write_seqcount_end(&tsk->vtime_seqcount); + 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