Re: kernel BUG at arch/x86/xen/mmu.c:1872

From: Teck Choon Giam <giamteckchoon@gmail.com>
To: MaoXiaoyun <tinnycloud@hotmail.com>
Cc: jeremy@goop.org, xen devel <xen-devel@lists.xensource.com>,
	keir@xen.org, ian.campbell@citrix.com, konrad.wilk@oracle.com,
	dave@ivt.com.au
Subject: Re: kernel BUG at arch/x86/xen/mmu.c:1872
Date: Mon, 11 Apr 2011 23:25:19 +0800	[thread overview]
Message-ID: <BANLkTimKWanNYTjrEHaik_Z1eLXptoN1kQ@mail.gmail.com> (raw)
In-Reply-To: <BLU157-w116F1BB57ABFDE535C7851DAA80@phx.gbl>

2011/4/11 MaoXiaoyun <tinnycloud@hotmail.com>:
> Hi:
>
>      I believe this is the fix at much extent.
>      Since I have my own test cases which with this patch, my test case will
> success in 30 rounds run.
>      Every round takes 8hours.  While without this patch, tests fail evey
> round in 15minutes.
>
>       So this really means fix most of the things.
>
>       But during running, I met another crash, from the log it it looks like
> has relation with
> this BUG, since the crash log shows it is tlb related and this BUG also tlb
> related.

Are you able to run another test with cpuidle=0 cpufreq=none in kernel
boot option?  Just curious whether can you reproduce the tlb bug when
you boot with cpuidle=0 cpufreq=none... ...

>
>       Well, I'm also have poor knowledge of kernel.
>       Hope someone from Xen Devel offer some help.
>
>       Many thanks.
>
>> Date: Mon, 11 Apr 2011 20:16:53 +0800
>> Subject: Re: kernel BUG at arch/x86/xen/mmu.c:1872
>> From: giamteckchoon@gmail.com
>> To: tinnycloud@hotmail.com
>> CC: xen-devel@lists.xensource.com; dave@ivt.com.au;
>> ian.campbell@citrix.com; konrad.wilk@oracle.com; jeremy@goop.org;
>> keir@xen.org
>>
>> >
>> > Hi,
>> >
>> > Sorry, since this mmu related BUG has been troubled me for very
>> > long... I really want to "kill" this BUG but my knowledge in kernel
>> > hacking and/or xen is very limited.
>> >
>> > While waiting for Jeremy or Konrad or others ...
>> >
>> > Many thanks for spending time to track down this mmu related BUG.  I
>> > have backported the commit from
>> >
>> > http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=64141da587241301ce8638cc945f8b67853156ec
>> > to 2.6.32.36 PVOPS kernel and patch attached.  I won't know whether
>> > did I backport it correctly nor does it affects anything.  I am
>> > currently testing the 2.6.32.36 PVOPS kernel with this patch applied
>> > and also unset CONFIG_DEBUG_PAGEALLOC.  Currently running testcrash.sh
>> > loop 1000 as I am unable to reproduce this mmu BUG 1872 in
>> > testcrash.sh loop 100.  Please note that when CONFIG_DEBUG_PAGEALLOC
>> > is unset, I can reproduce this mmu BUG 1872 easily within <50
>> > testcrash.sh loop cycle with PVOPS version 2.6.32.24 to 2.6.32.36
>> > kernel.  Now test with this backport patch to see whether I can
>> > reproduce this mmu BUG... ...
>> >
>> > Kindest regards,
>> > Giam Teck Choon
>> >
>>
>> I have tested with my backport patch and it is working fine as I am
>> unable to reproduce the mmu.c 1872 or 1860 bug with
>> CONFIG_DEBUG_PAGEALLOC not set. I tested with testcrash.sh loop 100
>> and 1000. Now doing testcrash.sh loop 10000.
>>
>> Xiaoyun, is it possible for you to test my patch and see whether can
>> you reproduce the mmu.c 1872/1860 bug?
>>
>> Can anyone of you review my patch?
>>
>> I will post a format patch according to
>> Documentation/SubmittingPatches in my next reply and hopefully can be
>> reviewed.
>>
>> Thanks.
>>
>> Kindest regards,
>> Giam Teck Choon
>