Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937176Ab3DJR6Y (ORCPT ); Wed, 10 Apr 2013 13:58:24 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33335 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934904Ab3DJR6X (ORCPT ); Wed, 10 Apr 2013 13:58:23 -0400 Message-ID: <5165A82E.8000609@zytor.com> Date: Wed, 10 Apr 2013 10:58:06 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: Ingo Molnar CC: Russ Anderson , Linus Torvalds , Robin Holt , Andrew Morton , Linux Kernel Mailing List , Shawn Guo , Thomas Gleixner , Ingo Molnar , the arch/x86 maintainers Subject: Re: [PATCH] Do not force shutdown/reboot to boot cpu. References: <20130403193743.GB29151@sgi.com> <20130408155701.GB19974@gmail.com> <5162EC1A.4050204@zytor.com> <20130408165916.GA3672@sgi.com> <20130410111620.GB29752@gmail.com> <20130410152911.GA3011@sgi.com> <20130410165934.GB21951@gmail.com> In-Reply-To: <20130410165934.GB21951@gmail.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 748 Lines: 22 On 04/10/2013 09:59 AM, Ingo Molnar wrote: > > 4 minutes bootup is 240 seconds, with 1024 CPUs that's about 240 msecs per CPU. > > That sounds a lot, given that unlike bootup there's not much real work to be done > during shutdown - we don't initialize anything, etc. > > Maybe much of those 240 msecs are spent in some stupid udelay loop or so, which > could be made parallel? > I wonder if it isn't calling stop_machine() 1024 times, each time rendezvousing all the still-active CPUs. -hpa -- 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/