Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760412Ab2FDLvr (ORCPT ); Mon, 4 Jun 2012 07:51:47 -0400 Received: from casper.infradead.org ([85.118.1.10]:55748 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757832Ab2FDLvp convert rfc822-to-8bit (ORCPT ); Mon, 4 Jun 2012 07:51:45 -0400 Message-ID: <1338810695.28282.30.camel@twins> Subject: Re: [PATCH] sched: balance_cpu to consider other cpus in its group as target of (pinned) task migration From: Peter Zijlstra To: Srivatsa Vaddagiri Cc: Prashanth Nageshappa , mingo@kernel.org, LKML , roland@kernel.org, efault@gmx.de, Ingo Molnar Date: Mon, 04 Jun 2012 13:51:35 +0200 In-Reply-To: <20120604114130.GA3386@linux.vnet.ibm.com> References: <4FCC4E3B.4090209@linux.vnet.ibm.com> <1338800454.2448.71.camel@twins> <20120604114130.GA3386@linux.vnet.ibm.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1556 Lines: 39 On Mon, 2012-06-04 at 17:11 +0530, Srivatsa Vaddagiri wrote: > * Peter Zijlstra [2012-06-04 11:00:54]: > > > > Signed-off-by: Srivatsa Vaddagiri > > > > Did vatsa write this patch? > > I wrote the first version of the patch which Prashanth took, tested, > fixed a bug and is finally publishing it. So yes, > > > If so, you forgot a From header, if not, wtf!? > > it is missing the From header. > > > OK, so previously we only pulled to ourselves, > > That't not entirely true isn't it i.e this_cpu need not equal > smp_processor_id even before this change. > > > now you make cpu x move > > from cpu y to cpu z. This changes the dynamic of the load-balancer, not > > a single word on that and its impact/ramifications. > > The other possibility is for the right sibling cpus to do load balance > in the same domain (noting that it needs to pull a task from another > sched_group to itself and ignoring balance_cpu). That seemed like a more > invasive change than this patch. We'd be happy to try any other approach > you have in mind. Thing is, first thing on Monday morning my brain don't work too fast. If I then get to basically reverse engineer a patch because people forgot to mention all the important bits, I get annoyed. So don't do that ;-) -- 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/