From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753546Ab1K1Qqx (ORCPT ); Mon, 28 Nov 2011 11:46:53 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:15083 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751533Ab1K1Qqv (ORCPT ); Mon, 28 Nov 2011 11:46:51 -0500 From: Glauber Costa To: linux-kernel@vger.kernel.org Cc: paul@paulmenage.org, lizf@cn.fujitsu.com, daniel.lezcano@free.fr, a.p.zijlstra@chello.nl, jbottomley@parallels.com, pjt@google.com, cgroups@vger.kernel.org, bsingharora@gmail.com, devel@openvz.org, kamezawa.hiroyu@jp.fujitsu.com, Glauber Costa Subject: [PATCH v2 2/3] Reuse cgroup's parent pointer Date: Mon, 28 Nov 2011 14:45:18 -0200 Message-Id: <1322498719-2255-3-git-send-email-glommer@parallels.com> X-Mailer: git-send-email 1.7.6.4 In-Reply-To: <1322498719-2255-1-git-send-email-glommer@parallels.com> References: <1322498719-2255-1-git-send-email-glommer@parallels.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We already have a pointer to the cgroup parent (whose data is more likely to be in the cache than this, anyway), so there is no need to have this one in cpuacct. This patch makes the underlying cgroup be used instead. Signed-off-by: Glauber Costa Reviewed-by: KAMEZAWA Hiroyuki CC: Paul Tuner CC: Peter Zijlstra --- kernel/sched/core.c | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e9e0c19..c36f926 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7840,7 +7840,6 @@ struct cpuacct { /* cpuusage holds pointer to a u64-type object on every cpu */ u64 __percpu *cpuusage; struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; - struct cpuacct *parent; }; struct cgroup_subsys cpuacct_subsys; @@ -7859,6 +7858,13 @@ static inline struct cpuacct *task_ca(struct task_struct *tsk) struct cpuacct, css); } +static inline struct cpuacct *parent_ca(struct cpuacct *ca) +{ + if (!ca || !ca->css.cgroup->parent) + return NULL; + return cgroup_ca(ca->css.cgroup->parent); +} + /* create a new cpu accounting group */ static struct cgroup_subsys_state *cpuacct_create( struct cgroup_subsys *ss, struct cgroup *cgrp) @@ -7877,9 +7883,6 @@ static struct cgroup_subsys_state *cpuacct_create( if (percpu_counter_init(&ca->cpustat[i], 0)) goto out_free_counters; - if (cgrp->parent) - ca->parent = cgroup_ca(cgrp->parent); - return &ca->css; out_free_counters: @@ -8046,7 +8049,7 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) ca = task_ca(tsk); - for (; ca; ca = ca->parent) { + for (; ca; ca = parent_ca(ca)) { u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); *cpuusage += cputime; } @@ -8088,7 +8091,7 @@ void cpuacct_update_stats(struct task_struct *tsk, do { __percpu_counter_add(&ca->cpustat[idx], val, batch); - ca = ca->parent; + ca = parent_ca(ca); } while (ca); rcu_read_unlock(); } -- 1.7.6.4