From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753361Ab1AUVOI (ORCPT ); Fri, 21 Jan 2011 16:14:08 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:33133 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751701Ab1AUVOG (ORCPT ); Fri, 21 Jan 2011 16:14:06 -0500 X-Authority-Analysis: v=1.1 cv=UQuFHoD2CPQ248x8AXEbKhr4z9AaDqApxmEl3BhfZ64= c=1 sm=0 a=ZNWVe3i0kLwA:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=47681EPdxkKAl8cyRE8A:9 a=_hINfl-VBxzuN86LwfQA:7 a=m_IVftNGMj904hvKuiACF-qJpl0A:4 a=PUjeQqilurYA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: 2.6.38-rc1 problems with khugepaged From: Steven Rostedt To: Andrea Arcangeli Cc: werner , akpm@linux-foundation.org, hannes@cmpxchg.org, idryomov@gmail.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, Minchan Kim , Johannes Weiner In-Reply-To: <20110121191757.GO9506@random.random> References: <20110121191757.GO9506@random.random> Content-Type: text/plain; charset="ISO-8859-15" Date: Fri, 21 Jan 2011 16:14:02 -0500 Message-ID: <1295644442.12215.4482.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ annoying plug ] On Fri, 2011-01-21 at 20:17 +0100, Andrea Arcangeli wrote: > On Fri, Jan 21, 2011 at 06:43:44AM -0400, werner wrote: > > 2.6.38-rc1-git1 runs normally with khugepaged switched > > OFF. Thus, khugepaged is the problem; as said if > > switched it on, during boot the computer becomes very slow > > and sticks almost. wl > > Sorry, looks like x86 32bit THP wasn't tested in all possible .config > (32bit support is upstream-only feature and because of lower userbase > it also got a lot less testing than 64bit support). > > Does it make any difference if you both disable CONFIG_PARAVIRT and > enable HIGHMEM64? > > For now keep THP off on 32bit, it should be trivial to reproduce so > fix will come soon. > > Minchan info shows it's an 32bit arch bug so don't be too worried > about it because it can't affect 64bit builds and it's not common code > bug and we'll fix it ASAP. Just want to mention that ktest.pl was included in this release, just for this purpose :) It does randconfigs (and other nice features) and will test various kernels. All you need is to have a test machine that can be remotely booted and have its console read via stdio from another machine. This happened to be how I triggered the bug. I would be happy to help anyone set it up. The config I used to test my box to do 10 runs of randconfig with a minimal config to make it boot, and then 10 runs of randconfig with the minimal config to make it boot and enable networking: ----- MACHINE = mitest # The TEST_START can override most defaults # do ten boot tests (minimum forced config settings as possible) TEST_START ITERATE 10 TEST_TYPE = boot BUILD_TYPE = randconfig MIN_CONFIG = /home/rostedt/work/autotest/configs/mitest/config-mitest-min CHECKOUT = origin/master # do ten boot and ssh hackbench tests (need network configs set) TEST_START ITERATE 10 TEST_TYPE = TEST BUILD_TYPE = randconfig MIN_CONFIG = /home/rostedt/work/autotest/configs/mitest/config-mitest-net CHECKOUT = origin/master TEST = ssh root@mitest /work/c/hackbench_32 50 # defaults to use when watching test (SKIP will make ktest ignore it) DEFAULTS SKIP REBOOT_ON_ERROR = 1 POWEROFF_ON_ERROR = 0 POWEROFF_ON_SUCCESS = 0 REBOOT_ON_SUCCESS = 1 DIE_ON_FAILURE = 1 #defaults to kick off at night, and shut down at the end DEFAULTS REBOOT_ON_ERROR = 0 POWEROFF_ON_ERROR = 1 POWEROFF_ON_SUCCESS = 1 REBOOT_ON_SUCCESS = 0 DIE_ON_FAILURE = 0 STORE_FAILURES = /home/rostedt/work/autotest/nobackup/failures # defaults for all tests DEFAULTS POWEROFF_AFTER_HALT = 60 CLEAR_LOG = 1 MIN_CONFIG = /home/rostedt/work/autotest/configs/mitest/config-mitest-min SSH_USER = root BUILD_DIR = /home/rostedt/work/autotest/nobackup/linux-test.git OUTPUT_DIR = /home/rostedt/work/autotest/nobackup/mitest BUILD_TARGET = arch/x86/boot/bzImage TARGET_IMAGE = /boot/vmlinuz-test POWER_CYCLE = /home/rostedt/work/autotest/cycle-mxtest CONSOLE = nc -d fedora 3001 LOCALVERSION = -test GRUB_MENU = Test Kernel MAKE_CMD = distmake-32 ARCH=i386 POWER_OFF = /home/rostedt/work/autotest/poweroff-mxtest BUILD_OPTIONS = -j20 LOG_FILE = /home/rostedt/work/autotest/nobackup/mitest/mitest.log TEST = ssh root@mitest cat /debug/tracing/trace ADD_CONFIG = /home/rostedt/work/autotest/configs/config-broken /home/rostedt/work/autotest/config-general ----- -- Steve