From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754065Ab2EWXdR (ORCPT ); Wed, 23 May 2012 19:33:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22118 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753789Ab2EWXdP (ORCPT ); Wed, 23 May 2012 19:33:15 -0400 Date: Thu, 24 May 2012 01:32:41 +0200 From: Andrea Arcangeli To: David Rientjes Cc: ethan zhao , linux-kernel@vger.kernel.org, Mel Gorman Subject: Re: Huge memory takes too long time to initialize on 4TB ? Message-ID: <20120523233240.GD4071@redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, May 22, 2012 at 08:38:04PM -0700, David Rientjes wrote: > On Wed, 23 May 2012, ethan zhao wrote: > > > Hi, aarcange > > > >    When I boot kernel 2.6.39-100.6.1.el6uek.x86_64(actually 3.0.26)on > > a 4TB memory machine, got following call trace, > > That shows huge memory take too long time to initialize ? any help ?, > > I compared the huge_memory.c code between 3.0.26 and the current > > 3.2.x, no change. > > > > This has nothing to do with mm/huge_memory.c, which is transparent > hugepages code, it's the lengthy iteration done for a very large > ZONE_NORMAL in setup_zone_migrate_reserve(). > > This should be fixed by 938929f14cb5 ("mm: reduce the amount of work done > when updating min_free_kbytes") and was merged in 3.3. Let us know if > there's still a problem after upgrading to either that or 3.4 I thought that was only a performance optimization, so if the oops is generated by a timeout it can fix it, so good idea to try it. But a timeout watchdog triggering exactly in spin_unlock sounds a bit unlikely occurence, so I assumed too long time here meant "wait forever because it crashed".