Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754251AbbDOOed (ORCPT ); Wed, 15 Apr 2015 10:34:33 -0400 Received: from cantor2.suse.de ([195.135.220.15]:60532 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752716AbbDOOeZ (ORCPT ); Wed, 15 Apr 2015 10:34:25 -0400 Date: Wed, 15 Apr 2015 15:34:20 +0100 From: Mel Gorman To: Peter Zijlstra Cc: Waiman Long , Linux-MM , Robin Holt , Nathan Zimmer , Daniel Rahn , Davidlohr Bueso , Dave Hansen , Tom Vaden , Scott Norton , LKML Subject: Re: [RFC PATCH 0/14] Parallel memory initialisation Message-ID: <20150415143420.GG14842@suse.de> References: <1428920226-18147-1-git-send-email-mgorman@suse.de> <552E6486.6070705@hp.com> <20150415142731.GI17717@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20150415142731.GI17717@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1191 Lines: 27 On Wed, Apr 15, 2015 at 04:27:31PM +0200, Peter Zijlstra wrote: > On Wed, Apr 15, 2015 at 09:15:50AM -0400, Waiman Long wrote: > > I had included your patch with the 4.0 kernel and booted up a 16-socket > > 12-TB machine. I measured the elapsed time from the elilo prompt to the > > availability of ssh login. Without the patch, the bootup time was 404s. It > > was reduced to 298s with the patch. So there was about 100s reduction in > > bootup time (1/4 of the total). > > But you cheat! :-) > > How long between power on and the elilo prompt? Do the 100 seconds > matter on that time scale? Calling it cheating is a *bit* harsh as the POST times vary considerably between manufacturers. While I'm interested in Waiman's answer, I'm told that those that really care about minimising reboot times will use kexec to avoid POST. The 100 seconds is 100 seconds, whether that is 25% in all cases is a different matter. -- Mel Gorman SUSE Labs -- 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/