From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f178.google.com (mail-ie0-f178.google.com [209.85.223.178]) by kanga.kvack.org (Postfix) with ESMTP id 5C29E6B0035 for ; Wed, 27 Nov 2013 18:58:00 -0500 (EST) Received: by mail-ie0-f178.google.com with SMTP id lx4so13525835iec.9 for ; Wed, 27 Nov 2013 15:58:00 -0800 (PST) Received: from relay.sgi.com (relay2.sgi.com. [192.48.179.30]) by mx.google.com with ESMTP id fi5si9567765icc.146.2013.11.27.15.57.57 for ; Wed, 27 Nov 2013 15:57:58 -0800 (PST) Date: Wed, 27 Nov 2013 17:58:16 -0600 From: Alex Thorlton Subject: Re: BUG: mm, numa: test segfaults, only when NUMA balancing is on Message-ID: <20131127235816.GG22514@sgi.com> References: <20131106131048.GC4877@suse.de> <20131107214838.GY3066@sgi.com> <20131108112054.GB5040@suse.de> <20131108221329.GD4236@sgi.com> <20131112212902.GA4725@sgi.com> <20131115000901.GB26002@suse.de> <20131115144504.GE26002@suse.de> <20131122212807.GR3062@sgi.com> <20131122230524.GB5285@suse.de> <20131123000924.GC5285@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131123000924.GC5285@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Sat, Nov 23, 2013 at 12:09:24AM +0000, Mel Gorman wrote: > On Fri, Nov 22, 2013 at 11:05:24PM +0000, Mel Gorman wrote: > > On Fri, Nov 22, 2013 at 03:28:07PM -0600, Alex Thorlton wrote: > > > > If the warning added by that patch does *not* trigger than can you also > > > > test this patch? It removes the barriers which should not be necessary > > > > and takes a reference tot he page before waiting on the lock. The > > > > previous version did not take the reference because otherwise the > > > > WARN_ON could not distinguish between a migration waiter and a surprise > > > > gup. > > > > > > Sorry for the delay; been a bit busy. I tested both of these patches on > > > top of this one (separately, of course): > > > > > > http://www.spinics.net/lists/linux-mm/msg63919.html > > > > > > I think that's the one you were referring to, if not send me a pointer > > > to the correct one and I'll give it another shot. Both patches still > > > segfaulted, so it doesn't appear that either of these solved the > > > problem. > > > > I see. Does THP have to be enabled or does it segfault even with THP > > disabled? It occurs with both THP on, and off. I get RCU stalls with THP on though. That's probably related to not having Kirill/Naoya's patches applied though. > > > > On a semi-related note, is the large machine doing anything with xpmem > or anything that depends on MMU notifiers to work properly? I noted > while looking at this that THP migration is not invalidating pages which > might be confusing a driver depending on it. I'm not using xpmem on any of the machines that I've been testing on, and I don't think that anything should be using MMU notifiers. - Alex -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org