Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965039Ab2J3Rjv (ORCPT ); Tue, 30 Oct 2012 13:39:51 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:31842 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964822Ab2J3Rjt (ORCPT ); Tue, 30 Oct 2012 13:39:49 -0400 X-Authority-Analysis: v=2.0 cv=NLdXCjGg c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=bYqEZP2IH2oA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=ED5KP61D5LcA:10 a=pGLkceISAAAA:8 a=VwQbUJbxAAAA:8 a=Z4Rwk6OoAAAA:8 a=20KFwNOVAAAA:8 a=9AzMRrQhAAAA:8 a=NufY4J3AAAAA:8 a=KKAkSRfTAAAA:8 a=JfrnYn6hAAAA:8 a=ftUzEednAAAA:8 a=sozttTNsAAAA:8 a=EUspDBNiAAAA:8 a=VnNF1IyMAAAA:8 a=fh4mg5NFAAAA:8 a=g28NZJHP-PzbozxbPmcA:9 a=PUjeQqilurYA:10 a=MSl-tDqOz04A:10 a=LI9Vle30uBYA:10 a=jbrJJM5MRmoA:10 a=jEp0ucaQiEUA:10 a=SxxB86fLhQ4A:10 a=re9sYKne76oA:10 a=WwgC8nHKvroA:10 a=3Rfx1nUSh_UA:10 a=QwxQZocgbLcA:10 a=x2szoZtqnggA:10 a=IG2fH9E8heMA:10 a=Im-eZXwrtqoA:10 a=jeBq3FmKZ4MA:10 a=Zh68SRI7RUMA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-ID: <1351618787.8467.136.camel@gandalf.local.home> Subject: Re: [PATCH 04/32] x86: New cpuset nohz irq vector From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Thomas Gleixner , Peter Zijlstra , Clark Williams , Frederic Weisbecker , Ingo Molnar , "Paul E. McKenney" , Mike Galbraith , Alessio Igor Bogani , Avi Kivity , Chris Metcalf , Christoph Lameter , Daniel Lezcano , Geoff Levand , Gilad Ben Yossef , Hakan Akkan , Kevin Hilman , Stephen Hemminger , Sven-Thorsten Dietrich Date: Tue, 30 Oct 2012 13:39:47 -0400 In-Reply-To: <20121029203847.242305452@goodmis.org> References: <20121029202711.062749374@goodmis.org> <20121029203847.242305452@goodmis.org> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2175 Lines: 57 On Mon, 2012-10-29 at 16:27 -0400, Steven Rostedt wrote: > plain text document attachment > (0004-x86-New-cpuset-nohz-irq-vector.patch) > From: Frederic Weisbecker > > We need a way to send an IPI (remote or local) in order to > asynchronously restart the tick for CPUs in nohz adaptive mode. > > This must be asynchronous such that we can trigger it with irqs > disabled. This must be usable as a self-IPI as well for example > in cases where we want to avoid random dealock scenario while > restarting the tick inline otherwise. > > This only settles the x86 backend. The core tick restart function > will be defined in a later patch. > > [CHECKME: Perhaps we instead need to use irq work for self IPIs. > But we also need a way to send async remote IPIs.] Probably just use irq_work for self ipis, and normal ipis for other CPUs. Also, what reason do we have to force a task out of nohz? IOW, do we really need this? Also, perhaps we could just tag onto the schedule_ipi() function instead of having to create a new IPI for all archs? -- Steve > > Signed-off-by: Frederic Weisbecker > Cc: Alessio Igor Bogani > Cc: Andrew Morton > Cc: Avi Kivity > Cc: Chris Metcalf > Cc: Christoph Lameter > Cc: Daniel Lezcano > Cc: Geoff Levand > Cc: Gilad Ben Yossef > Cc: Hakan Akkan > Cc: Ingo Molnar > Cc: Kevin Hilman > Cc: Max Krasnyansky > Cc: Paul E. McKenney > Cc: Peter Zijlstra > Cc: Stephen Hemminger > Cc: Steven Rostedt > Cc: Sven-Thorsten Dietrich > Cc: Thomas Gleixner -- 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/