From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from digeo-nav01.digeo.com (digeo-nav01.digeo.com [192.168.1.233]) by packet.digeo.com (8.9.3+Sun/8.9.3) with SMTP id OAA08179 for ; Wed, 9 Oct 2002 14:32:27 -0700 (PDT) Message-ID: <3DA4A06A.B84D4C05@digeo.com> Date: Wed, 09 Oct 2002 14:32:26 -0700 From: Andrew Morton MIME-Version: 1.0 Subject: Re: Hangs in 2.5.41-mm1 References: <3DA48EEA.8100302C@digeo.com> <1034195372.30973.64.camel@plars> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Larson Cc: linux-mm List-ID: Paul Larson wrote: > > On Wed, 2002-10-09 at 15:17, Andrew Morton wrote: > > Paul Larson wrote: > > > echo 768 > /proc/sys/vm/nr_hugepages > > > > Paul, this is not very clear to me, sorry. > Sorry about that, let me try to restate it better. First let me add > though, these have been somewhat random and hard to reproduce the same > way every time, but if I run this test enough though, I eventually get > it to lock up cold. > > Here are the situations where I saw it happen so far under 2.5.41-mm1: > > Case 1: > from ltp, 'runalltests.sh -l /tmp/mm1.log |tee /tmp/mm1.out > shmt01 (attached test from before) > shmt01& (repeated 10 times) > echo 768 > /proc/sys/vm/nr_hugepages > *hang* > > Case 2: > cold boot > echo 768 > /proc/sys/vm/nr_hugepages > echo 1610612736 > /proc/sys/kernel/shmmax > shmt01 -s 1610612736& > shmt01 (immediately after starting the previous command) > *hang* OK, thanks. > > There is a locks-up-for-ages bug in refill_inactive_zone() - could > > be that. Dunno. > I'm not aware of that one, do you know of a reliable way to reproduce that? You need to torture it. It happens when there's a huge amount of mapped memory in a zone and the `swappiness' knob is set low. We end up doing a ton of scanning of the active list, but not actually doing anything. Fix is to only scan a little bit, then fall back and scan the inactive list a bit, let the scanning priority increase until it's high enough to trigger reclaim of mapped memory. -mm2 will cure all ills ;) -- 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/