From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: Re: Re: Test results for save/restore with upstream pv_ops domU kernels, 2.6.32.7 works OK Date: Mon, 01 Feb 2010 16:26:05 +0100 Message-ID: <4B66F28D.4070109@redhat.com> References: <20100128212559.GF2861@reaktio.net> <1264761332.2965.4889.camel@zakaz.uk.xensource.com> <20100129105338.GM2861@reaktio.net> <20100201151010.GZ2861@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20100201151010.GZ2861@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: =?ISO-8859-1?Q?Pasi_K=E4rkk=E4inen?= Cc: Jeremy Fitzhardinge , "xen-devel@lists.xensource.com" , Ian Campbell List-Id: xen-devel@lists.xenproject.org On 02/01/2010 04:10 PM, Pasi K=E4rkk=E4inen wrote: > On Fri, Jan 29, 2010 at 12:53:38PM +0200, Pasi K=E4rkk=E4inen wrote: >> On Fri, Jan 29, 2010 at 10:35:32AM +0000, Ian Campbell wrote: >>> On Thu, 2010-01-28 at 21:25 +0000, Pasi K=E4rkk=E4inen wrote: >>>> Hello, >>>> >>>> I just tried some save/restore tests with Fedora 12 Linux 2.6.31.12 = kernels. >>>> The exact Fedora kernel versions are: 2.6.31.12-174.2.3.fc12.i686.PA= E and 2.6.31.12-174.2.3.fc12.x86_64. >>>> >>>> Dom0 for these tests was CentOS 5.4 (Xen 3.1.2). >>>> >>>> - F12 32bit 1vcpu PV guest:=20 >>>> save+restore OK, BUG() in guest dmesg after restore [1] >>>> >>>> - F12 64bit 1vcpu PV guest: >>>> save+restore OK, BUG() in guest dmesg after restore [2] >>> >>> I think those are the same underlying bug and are fixed by=20 >>> http://git.kernel.org/?p=3Dlinux/kernel/git/jeremy/xen.git;a=3Dcommit= ;h=3D777df2b017ef34b2d1a172bf769582158839a860 >>> >> >> Ok.=20 >> >> There was also this traceback in the beginning of boot, on all 32bit/6= 4bit, 1vcpu2/vcpu guest combinations: >> >> Performance Counters: Core2 events, Intel PMU driver. >> ------------[ cut here ]------------ >> WARNING: at arch/x86/kernel/apic/apic.c:247 native_apic_write_dummy+0x= 32/0x3e() (Not tainted) >> Modules linked in: >> Pid: 0, comm: swapper Not tainted 2.6.31.12-174.2.3.fc12.i686.PAE #1 >> Call Trace: >> [] warn_slowpath_common+0x70/0x87 >> [] ? native_apic_write_dummy+0x32/0x3e >> [] warn_slowpath_null+0x12/0x15 >> [] native_apic_write_dummy+0x32/0x3e >> [] perf_counters_lapic_init+0x30/0x32 >> [] init_hw_perf_counters+0x2bc/0x355 >> [] identify_boot_cpu+0x21/0x23 >> [] check_bugs+0xb/0xdc >> [] ? delayacct_init+0x47/0x4c >> [] start_kernel+0x31c/0x330 >> [] i386_start_kernel+0x70/0x77 >> [] xen_start_kernel+0x4b9/0x4c1 >> [] ? syscall_exit+0x1/0x16 >> ---[ end trace a7919e7f17c0a725 ]--- >> >> Full boot logs here: >> http://pasik.reaktio.net/xen/debug/fedora/ >> >=20 >=20 > This boot-time traceback disappeared when I updated the guest to 2.6.32= .7. >=20 >=20 >> >>>> >>>> - F12 32bit 2vcpu PV guest: >>>> save doesn't work, guest stays as "migrating-f12test32" in "xm list= " forever and has to be "xm destroy"ed. >>>> >>>> - F12 64bit 2vcpu PV guest: >>>> save doesn't work, guest stays as "migrating-f12test64" in "xm list= " forever and has to be "xm destroy"ed. >>>> >>>> >>>> What's the best way to debug failing "xm save" ? There was no errors= in "xm log", or in "xm dmesg". >>> >>> I think you might see some stuff in /var/log/xen/something but I don'= t >>> have any particular tips apart from "add printf/printk". >>> >> >> I'll check /var/log/xen/. >> >>>> Also the guest "xm console" doesn't show anything before it dies. >>>> >>>> Is it possible some of the save/restore related patches didn't make = it to 2.6.31.x stable kernels?=20 >>> >>> AFAIK they only went into the 2.6.32 stable branch. Unfortunately I >>> think the 2.6.31 stable series has come to an end now. >>> >> >> Ok. I'll test 2.6.32.latest aswell. >> >=20 > I grabbed upstream kernel.org Linux 2.6.32.7, and tested the following = combinations: >=20 > - F12 32bit 1vcpu PV guest > - F12 32bit 2vcpu PV guest > - F12 64bit 1vcpu PV guest > - F12 64bit 2vcpu PV guest >=20 > save+restore was successfull for all of the above guests running 2.6.32= .7.=20 > No BUGs or tracebacks anymore. >=20 > Any tips for git magic to get all the recent save/restore fixes that we= nt to 2.6.32.x, > so I could send them to Fedora people to apply to F12 kernel?=20 >=20 This is great news, but it might a good idea to try 2 or more save-restore rounds in row first, if you haven't already. In the past I've seen 1 save/restore work, but then the 2nd round fail. Although, usually there's some symptom of badness on the 1st round as well. Thanks, Andrew