From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753188Ab3LTX3u (ORCPT ); Fri, 20 Dec 2013 18:29:50 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.226]:3162 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751259Ab3LTX3t (ORCPT ); Fri, 20 Dec 2013 18:29:49 -0500 Date: Fri, 20 Dec 2013 18:29:46 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: tglx@linutronix.de, mingo@redhat.com, oleg@redhat.com, fweisbec@gmail.com, darren@dvhart.com, johan.eker@ericsson.com, p.faure@akatech.ch, linux-kernel@vger.kernel.org, claudio@evidence.eu.com, michael@amarulasolutions.com, fchecconi@gmail.com, tommaso.cucinotta@sssup.it, juri.lelli@gmail.com, nicola.manica@disi.unitn.it, luca.abeni@unitn.it, dhaval.giani@gmail.com, hgu1972@gmail.com, paulmck@linux.vnet.ibm.com, raistlin@linux.it, insop.song@gmail.com, liming.wang@windriver.com, jkacur@redhat.com Subject: Re: [PATCH 09/13] sched: Add bandwidth management for sched_dl Message-ID: <20131220182946.09ca0f04@gandalf.local.home> In-Reply-To: <20131220214413.GF7959@laptop.programming.kicks-ass.net> References: <20131217122720.950475833@infradead.org> <20131217123353.180539582@infradead.org> <20131218165508.GB30183@twins.programming.kicks-ass.net> <20131220171343.GL2480@laptop.programming.kicks-ass.net> <20131220123707.44fb7192@gandalf.local.home> <20131220174200.GX16438@laptop.programming.kicks-ass.net> <20131220132323.524cf2b1@gandalf.local.home> <20131220214413.GF7959@laptop.programming.kicks-ass.net> X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.22; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.130:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Dec 2013 22:44:13 +0100 Peter Zijlstra wrote: > @@ -5056,10 +5018,28 @@ static int sched_cpu_inactive(struct not > switch (action & ~CPU_TASKS_FROZEN) { > case CPU_DOWN_PREPARE: > set_cpu_active((long)hcpu, false); > - return NOTIFY_OK; > - default: > - return NOTIFY_DONE; > + break; > } > + > + switch (action) { > + case CPU_DOWN_PREPARE: /* explicitly allow suspend */ Instead of the double switch (which is quite confusing), what about just adding: if (!(action & CPU_TASKS_FROZEN)) I mean, the above switch gets called for both cases, this only gets called for the one case. This case is a subset of the above. I don't see why an if () would not be better than a double (confusing) switch(). Also, it seems that this change also does not return NOTIFY_DONE if something other than CPU_DOWN_PREPARE is passed in. -- Steve > + { > + struct dl_bw *dl_b = dl_bw_of(cpu); > + bool overflow; > + int cpus; > + > + raw_spin_lock_irqsave(&dl_b->lock, flags); > + cpus = dl_bw_cpus(cpu); > + overflow = __dl_overflow(dl_b, cpus, 0, 0); > + raw_spin_unlock_irqrestore(&dl_b->lock, flags); > + > + if (overflow) > + return notifier_from_errno(-EBUSY); > + } > + break; > + } > + > + return NOTIFY_OK; > } > > static int __init migration_init(void)