Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753771Ab3FYSwG (ORCPT ); Tue, 25 Jun 2013 14:52:06 -0400 Received: from relay3.sgi.com ([192.48.152.1]:55022 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751490Ab3FYSwE (ORCPT ); Tue, 25 Jun 2013 14:52:04 -0400 Message-ID: <51C9E6CD.5080508@sgi.com> Date: Tue, 25 Jun 2013 11:51:57 -0700 From: Mike Travis User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: "H. Peter Anvin" CC: Ingo Molnar , Nathan Zimmer , holt@sgi.com, rob@landley.net, tglx@linutronix.de, mingo@redhat.com, yinghai@kernel.org, akpm@linux-foundation.org, gregkh@linuxfoundation.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Peter Zijlstra Subject: Re: [RFC 2/2] x86_64, mm: Reinsert the absent memory References: <1371831934-156971-1-git-send-email-nzimmer@sgi.com> <1371831934-156971-3-git-send-email-nzimmer@sgi.com> <20130623092840.GB13445@gmail.com> <20130624203657.GA107621@asylum.americas.sgi.com> <20130625073819.GC11420@gmail.com> <51C9D1D6.20405@sgi.com> <51C9E4B7.2000007@zytor.com> In-Reply-To: <51C9E4B7.2000007@zytor.com> 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: 1982 Lines: 54 On 6/25/2013 11:43 AM, H. Peter Anvin wrote: > On 06/25/2013 10:22 AM, Mike Travis wrote: >> >> On 6/25/2013 12:38 AM, Ingo Molnar wrote: >>> >>> * Nathan Zimmer wrote: >>> >>>> On Sun, Jun 23, 2013 at 11:28:40AM +0200, Ingo Molnar wrote: >>>>> >>>>> That's 4.5 GB/sec initialization speed - that feels a bit slow and the >>>>> boot time effect should be felt on smaller 'a couple of gigabytes' >>>>> desktop boxes as well. Do we know exactly where the 2 hours of boot >>>>> time on a 32 TB system is spent? >>>> >>>> There are other several spots that could be improved on a large system >>>> but memory initialization is by far the biggest. >>> >>> My feeling is that deferred/on-demand initialization triggered from the >>> buddy allocator is the better long term solution. >> >> I haven't caught up with all of Nathan's changes yet (just >> got back from vacation), but there was an option to either >> start the memory insertion on boot, or trigger it later >> using the /sys/.../memory interface. There is also a monitor >> program that calculates the memory insertion rate. This was >> extremely useful to determine how changes in the kernel >> affected the rate. >> > > Sorry, I *totally* did not follow that comment. It seemed like a > complete non-sequitur? > > -hpa It was I who was not following the question. I'm still reverting back to "work mode". [There is more code in a separate patch that Nate has not sent yet that instructs the kernel to start adding memory as early as possible, or not. That way you can start the insertion process later and monitor it's progress to determine how changes in the kernel affect that process. It is controlled by a separate CONFIG option.] > > -- 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/