Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946049Ab3FUUkf (ORCPT ); Fri, 21 Jun 2013 16:40:35 -0400 Received: from relay1.sgi.com ([192.48.179.29]:37863 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945951Ab3FUUke (ORCPT ); Fri, 21 Jun 2013 16:40:34 -0400 Date: Fri, 21 Jun 2013 15:40:33 -0500 From: Nathan Zimmer To: Yinghai Lu Cc: Nathan Zimmer , Greg KH , "H. Peter Anvin" , Robin Holt , Mike Travis , Rob Landley , Thomas Gleixner , Ingo Molnar , Andrew Morton , the arch/x86 maintainers , linux-doc@vger.kernel.org, Linux Kernel Mailing List Subject: Re: [RFC 0/2] Delay initializing of large sections of memory Message-ID: <20130621204032.GA21126@gulag1.americas.sgi.com> References: <1371831934-156971-1-git-send-email-nzimmer@sgi.com> <20130621165142.GA32125@kroah.com> <51C48745.9030304@zytor.com> <20130621185056.GA23473@kroah.com> <51C4A726.1090300@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1651 Lines: 38 On Fri, Jun 21, 2013 at 01:28:11PM -0700, Yinghai Lu wrote: > On Fri, Jun 21, 2013 at 12:19 PM, Nathan Zimmer wrote: > > On 06/21/2013 02:10 PM, Yinghai Lu wrote: > >> in this way we can keep all numa etc on the place when online ram, cpu, > >> pci... > >> > >> For example if we have 32 sockets system, most time for boot is with > >> *BIOS* > >> instead of OS. In those kind of system boot is like this way: > >> only first two sockets get booted from bios to OS. > >> later use hot add every other two sockets. > >> > >> that will also make BIOS simpler, and it need to support hot-add for > >> services purpose anyway. > >> > > Yes the hot add path was one option we looked at and it did shorten boot > > times but the goal I had here is to get from power on to having the full > > machine available as quick as possible. Several clients need significant > > portions of ram for their key workloads. So that guided my thoughts on this > > patch. > > you mean boot small number sockets + hot add still take more time? > hot add ram still in serialize mode? > > Yinghai Yes the hot add path is still fairly serial. lock_memory_hotplug() is still a global lock, which effectivly serializes online pages. Since the hotplug lock could done per node but for that to be effective something would need to be done with lock_system_sleep() since is called by lock_memory_hotplug(). Nate -- 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/