From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id 9D7A36B0035 for ; Thu, 20 Oct 2011 02:30:32 -0400 (EDT) From: =?utf-8?q?Pawe=C5=82_Sikora?= Subject: Re: kernel 3.0: BUG: soft lockup: find_get_pages+0x51/0x110 Date: Thu, 20 Oct 2011 08:30:21 +0200 References: <201110122012.33767.pluto@agmk.net> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <201110200830.22062.pluto@agmk.net> Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Linus Torvalds , Mel Gorman , Andrea Arcangeli , Andrew Morton , linux-mm@kvack.org, jpiszcz@lucidpixels.com, arekm@pld-linux.org, linux-kernel@vger.kernel.org On Wednesday 19 of October 2011 21:42:15 Hugh Dickins wrote: > On Wed, 19 Oct 2011, Linus Torvalds wrote: > > On Wed, Oct 19, 2011 at 12:43 AM, Mel Gorman wrote: > > > > > > My vote is with the migration change. While there are occasionally > > > patches to make migration go faster, I don't consider it a hot path. > > > mremap may be used intensively by JVMs so I'd loathe to hurt it. > > > > Ok, everybody seems to like that more, and it removes code rather than > > adds it, so I certainly prefer it too. Pawel, can you test that other > > patch (to mm/migrate.c) that Hugh posted? Instead of the mremap vma > > locking patch that you already verified for your setup? > > > > Hugh - that one didn't have a changelog/sign-off, so if you could > > write that up, and Pawel's testing is successful, I can apply it... > > Looks like we have acks from both Andrea and Mel. > > Yes, I'm glad to have that input from Andrea and Mel, thank you. > > Here we go. I can't add a Tested-by since Pawel was reporting on the > alternative patch, but perhaps you'll be able to add that in later. > > I may have read too much into Pawel's mail, but it sounded like he > would have expected an eponymous find_get_pages() lockup by now, > and was pleased that this patch appeared to have cured that. > > I've spent quite a while trying to explain find_get_pages() lockup by > a missed migration entry, but I just don't see it: I don't expect this > (or the alternative) patch to do anything to fix that problem. I won't > mind if it magically goes away, but I expect we'll need more info from > the debug patch I sent Justin a couple of days ago. the latest patch (mm/migrate.c) applied on 3.0.4 also survives points 1) and 2) described previously (https://lkml.org/lkml/2011/10/18/427), so please apply it to the upstream/stable git tree. from the other side, both patches don't help for 3.0.4+vserver host soft-lock which dies in few hours of stressing. iirc this lock has started with 2.6.38. is there any major change in memory managment area in 2.6.38 that i can bisect and test with vserver? BR, PaweA?. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org