Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758463AbcCVIjo (ORCPT ); Tue, 22 Mar 2016 04:39:44 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:9899 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1758355AbcCVIjY (ORCPT ); Tue, 22 Mar 2016 04:39:24 -0400 X-IronPort-AV: E=Sophos;i="5.22,518,1449504000"; d="scan'208";a="4840131" From: Zhao Lei To: , Tejun Heo , Peter Zijlstra CC: Zhao Lei Subject: [PATCH v4 2/4] cpuacct: small restruct for cpuacct Date: Tue, 22 Mar 2016 16:37:06 +0800 Message-ID: <7b8fa3fc1f7f60fb1bb70308231e5a2079129abf.1458635566.git.zhaolei@cn.fujitsu.com> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-yoursite-MailScanner-ID: 500A6408D264.A5085 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: zhaolei@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2454 Lines: 90 1: Use for() instead of while() loop in some functions to make code simple. 2: Use this_cpu_ptr() instead of per_cpu_ptr() to make code clean with little performance up. Suggested-by: Peter Zijlstra Signed-off-by: Zhao Lei --- kernel/sched/cpuacct.c | 28 +++++----------------------- kernel/sched/cpuacct.h | 4 ++-- 2 files changed, 7 insertions(+), 25 deletions(-) diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 9c2bbf7..434c2fa 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -238,23 +238,10 @@ static struct cftype files[] = { void cpuacct_charge(struct task_struct *tsk, u64 cputime) { struct cpuacct *ca; - int cpu; - - cpu = task_cpu(tsk); rcu_read_lock(); - - ca = task_ca(tsk); - - while (true) { - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - *cpuusage += cputime; - - ca = parent_ca(ca); - if (!ca) - break; - } - + for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) + *this_cpu_ptr(ca->cpuusage) += cputime; rcu_read_unlock(); } @@ -263,18 +250,13 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) * * Note: it's the caller that updates the account of the root cgroup. */ -void cpuacct_account_field(struct task_struct *p, int index, u64 val) +void cpuacct_account_field(struct task_struct *tsk, int index, u64 val) { - struct kernel_cpustat *kcpustat; struct cpuacct *ca; rcu_read_lock(); - ca = task_ca(p); - while (ca != &root_cpuacct) { - kcpustat = this_cpu_ptr(ca->cpustat); - kcpustat->cpustat[index] += val; - ca = parent_ca(ca); - } + for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca)) + this_cpu_ptr(ca->cpustat)->cpustat[index] += val; rcu_read_unlock(); } diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h index ed60562..ba72807 100644 --- a/kernel/sched/cpuacct.h +++ b/kernel/sched/cpuacct.h @@ -1,7 +1,7 @@ #ifdef CONFIG_CGROUP_CPUACCT extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); -extern void cpuacct_account_field(struct task_struct *p, int index, u64 val); +extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); #else @@ -10,7 +10,7 @@ static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) } static inline void -cpuacct_account_field(struct task_struct *p, int index, u64 val) +cpuacct_account_field(struct task_struct *tsk, int index, u64 val) { } -- 1.8.5.1