From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753307Ab1HQCoH (ORCPT ); Tue, 16 Aug 2011 22:44:07 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:60698 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753194Ab1HQCoB (ORCPT ); Tue, 16 Aug 2011 22:44:01 -0400 Message-ID: <4E4B2B06.4010108@cn.fujitsu.com> Date: Wed, 17 Aug 2011 10:44:22 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc14 Thunderbird/3.1.4 MIME-Version: 1.0 To: Frederic Weisbecker CC: LKML , Andrew Morton , Paul Menage , Johannes Weiner , Aditya Kali , Oleg Nesterov Subject: Re: [PATCH 8/8] res_counter: Allow charge failure pointer to be null References: <1311956010-32076-1-git-send-email-fweisbec@gmail.com> <1311956010-32076-9-git-send-email-fweisbec@gmail.com> In-Reply-To: <1311956010-32076-9-git-send-email-fweisbec@gmail.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-08-17 10:42:43, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-08-17 10:42:45, Serialize complete at 2011-08-17 10:42:45 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Frederic Weisbecker wrote: > So that callers of res_counter_charge() don't have to create and > pass this pointer even if they aren't interested in it. > Why not make this change early, or even do this in "[PATCH 5/8]". > Signed-off-by: Frederic Weisbecker > Cc: Paul Menage > Cc: Li Zefan > Cc: Johannes Weiner > Cc: Aditya Kali > Cc: Oleg Nesterov > --- > kernel/cgroup_task_counter.c | 6 ++---- > kernel/res_counter.c | 6 ++++-- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/kernel/cgroup_task_counter.c b/kernel/cgroup_task_counter.c > index 7f12ac9..dacc4a9 100644 > --- a/kernel/cgroup_task_counter.c > +++ b/kernel/cgroup_task_counter.c > @@ -93,11 +93,10 @@ static int task_counter_can_attach_task(struct cgroup *cgrp, struct cgroup *old_ > { > struct res_counter *res = cgroup_task_counter_res(cgrp); > struct res_counter *old_res = cgroup_task_counter_res(old_cgrp); > - struct res_counter *limit_fail_at; > > common_ancestor = res_counter_common_ancestor(res, old_res); > > - return res_counter_charge_until(res, common_ancestor, 1, &limit_fail_at); > + return res_counter_charge_until(res, common_ancestor, 1, NULL); > } > > static void task_counter_cancel_attach_task(struct cgroup *cgrp, struct task_struct *tsk) > @@ -154,13 +153,12 @@ int cgroup_task_counter_fork(struct task_struct *child) > { > struct cgroup_subsys_state *css = child->cgroups->subsys[tasks_subsys_id]; > struct cgroup *cgrp = css->cgroup; > - struct res_counter *limit_fail_at; > > /* Optimize for the root cgroup case, which doesn't have a limit */ > if (!cgrp->parent) > return 0; > > - return res_counter_charge(cgroup_task_counter_res(cgrp), 1, &limit_fail_at); > + return res_counter_charge(cgroup_task_counter_res(cgrp), 1, NULL); > } > > struct cgroup_subsys tasks_subsys = { > diff --git a/kernel/res_counter.c b/kernel/res_counter.c > index 725dfa6..7eac803 100644 > --- a/kernel/res_counter.c > +++ b/kernel/res_counter.c > @@ -43,14 +43,16 @@ int res_counter_charge_until(struct res_counter *counter, > unsigned long flags; > struct res_counter *c, *u; > > - *limit_fail_at = NULL; > + if (limit_fail_at) > + *limit_fail_at = NULL; > local_irq_save(flags); > for (c = counter; c != limit; c = c->parent) { > spin_lock(&c->lock); > ret = res_counter_charge_locked(c, val); > spin_unlock(&c->lock); > if (ret < 0) { > - *limit_fail_at = c; > + if (limit_fail_at) > + *limit_fail_at = c; > goto undo; > } > }