Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753017Ab1BVOCI (ORCPT ); Tue, 22 Feb 2011 09:02:08 -0500 Received: from mailout-de.gmx.net ([213.165.64.23]:40094 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752906Ab1BVOCE (ORCPT ); Tue, 22 Feb 2011 09:02:04 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX19aXGESAU9aSJTad/QbbZzQHBeS6/hpQ4YCypd0Y4 VZ/DY6WWf0rnTC Subject: Re: [PATCH V2] sched, autogroup: always show autogroup name in sched_debug From: Mike Galbraith To: Yong Zhang Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Ingo Molnar In-Reply-To: <20110222121002.GA2100@zhy> References: <1298185696-4403-1-git-send-email-yong.zhang0@gmail.com> <1298185696-4403-6-git-send-email-yong.zhang0@gmail.com> <1298207379.7998.11.camel@marge.simson.net> <20110220141003.GA6006@zhy> <1298222533.7881.15.camel@marge.simson.net> <1298306175.24121.14.camel@twins> <1298368566.2217.18.camel@twins> <20110222121002.GA2100@zhy> Content-Type: text/plain; charset="UTF-8" Date: Tue, 22 Feb 2011 15:02:00 +0100 Message-ID: <1298383320.8036.5.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.1.2 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2560 Lines: 75 On Tue, 2011-02-22 at 20:10 +0800, Yong Zhang wrote: > On Tue, Feb 22, 2011 at 10:56:06AM +0100, Peter Zijlstra wrote: > > On Tue, 2011-02-22 at 11:13 +0800, Yong Zhang wrote: > > > So show autogroup name always. But for the root group, > > > its name will dance between "cfs_rq[cpu]:" and > > > "cfs_rq[cpu]:/autogroup-0" according to > > > sysctl_sched_autogroup_enabled. > > > > Would it make sense to force the root group to always be a !autogroup? > > Hmmm, I think it's ok. Yup, it's not an autogroup, so let's stop claiming it. sched, autogroup: stop claiming ownership of the root task group. Disown it, and only display autogroup association if one exists. Signed-off-by: Mike Galbraith diff --git a/kernel/sched_autogroup.c b/kernel/sched_autogroup.c index 9fb6562..506faa0 100644 --- a/kernel/sched_autogroup.c +++ b/kernel/sched_autogroup.c @@ -12,7 +12,6 @@ static atomic_t autogroup_seq_nr; static void __init autogroup_init(struct task_struct *init_task) { autogroup_default.tg = &root_task_group; - root_task_group.autogroup = &autogroup_default; kref_init(&autogroup_default.kref); init_rwsem(&autogroup_default.lock); init_task->signal->autogroup = &autogroup_default; @@ -130,7 +129,7 @@ task_wants_autogroup(struct task_struct *p, struct task_group *tg) static inline bool task_group_is_autogroup(struct task_group *tg) { - return tg != &root_task_group && tg->autogroup; + return !!tg->autogroup; } static inline struct task_group * @@ -247,10 +246,14 @@ void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m) { struct autogroup *ag = autogroup_task_get(p); + if (!task_group_is_autogroup(ag->tg)) + goto out; + down_read(&ag->lock); seq_printf(m, "/autogroup-%ld nice %d\n", ag->id, ag->nice); up_read(&ag->lock); +out: autogroup_kref_put(ag); } #endif /* CONFIG_PROC_FS */ @@ -258,9 +261,7 @@ void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m) #ifdef CONFIG_SCHED_DEBUG static inline int autogroup_path(struct task_group *tg, char *buf, int buflen) { - int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled); - - if (!enabled || !tg->autogroup) + if (!task_group_is_autogroup(tg)) return 0; return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/