Re: [Bugme-new] [Bug 15709] New: swapper page allocation failure

["Michael S. Tsirkin" <mst@redhat.com>]

So, it's an NFS-related regression, which is consistent with the bisect
results. I guess someone who knows about NFS will have to look at it...
BTW, you probably want to label the bug as regression.

On Sun, Apr 25, 2010 at 10:41:59PM +0200, Robert Wimmer wrote:
> I've added CONFIG_KALLSYMS and CONFIG_KALLSYMS_ALL
> to my .config. I've uploaded the dmesg output. Maybe it
> helps a little bit:
> 
> https://bugzilla.kernel.org/attachment.cgi?id=26138
> 
> - Robert
> 
> 
> On 04/25/10 11:18, Michael S. Tsirkin wrote:
> > On Fri, Apr 23, 2010 at 07:26:52AM +0200, Robert Wimmer wrote:
> >   
> >>> I'm not sure why the lockup backtrace does not show function names -
> >>> is the kernel stripped?
> >>>       
> >> I'm building the kernels always with "genkernel" a Gentoo
> >> helper programm for kernel building. But I've looked into
> >> the log file of genkernel and there is nothing mentioned about
> >> striping the kernel. There will be a future release of genkernel
> >> which supports this but this is currently not the case. Since
> >> I haven't stripped the kernel I would answer no. Maybe a
> >> kernel option which should be enabled?
> >>
> >> Thanks!
> >> Robert
> >>
> >>     
> > Hmm. I have these
> > CONFIG_KALLSYMS=y
> > CONFIG_KALLSYMS_ALL=y
> > CONFIG_KALLSYMS_EXTRA_PASS=y
> > # CONFIG_STRIP_ASM_SYMS is not set
> >
> >
> >   
> >>
> >> On 04/22/10 12:03, Michael S. Tsirkin wrote:
> >>     
> >>> On Thu, Apr 22, 2010 at 01:31:06PM +0200, kernel wrote:
> >>>   
> >>>       
> >>>> Maybe some comments to my former mail about what I've done:
> >>>> I started with a fresh clone (deleted the old /usr/src/linux
> >>>> of course). 
> >>>>
> >>>> git clone
> >>>> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git linux
> >>>>
> >>>> Then I started bisect
> >>>>
> >>>> git bisect start 'v2.6.31' 'v2.6.30'
> >>>>
> >>>> and build the first kernel and then marked kernels which
> >>>> "crashed" with "soft lockup" or "swapper page allocation failure"
> >>>> as bad and the other ones as good. Before I've compiled
> >>>> a new kernel I've always done a "make mrproper". I don't know
> >>>> if this is needed but thought it wouldn't hurt.
> >>>>
> >>>> For me it was not clear that maybe I should have had stopped
> >>>> testing after the first commit that came up with a "swapper
> >>>> page allocation failure". It was only one commit which cased
> >>>> the allocation failure. All the other commits marked as bad
> >>>> came up with a soft lockup. But I thought it is important to
> >>>> find the earliest commit which crashes. So should I find out
> >>>> the commit with the allocation failure?
> >>>>     
> >>>>         
> >>> I think you did the right thing. We'll have to
> >>> figure out soft lockup thing, then if page allocation failure
> >>> turns out to be a different issue, look at it.
> >>>
> >>>   
> >>>       
> >>>> As you requested I've now done now a
> >>>>
> >>>> git checkout c02d7adf8c5429727a98bad1d039bccad4c61c50
> >>>>
> >>>> which ended with a soft lockup within 3 min. after starting
> >>>> the VM (see
> >>>> https://bugzilla.kernel.org/attachment.cgi?id=26089&action=edit)
> >>>> with this kernel.
> >>>>     
> >>>>         
> >>> I'm not sure why the lockup backtrace does not show function names -
> >>> is the kernel stripped?
> >>>
> >>>   
> >>>       
> >>>> Then I've done a
> >>>>
> >>>> git checkout cf8d2c11cb77f129675478792122f50827e5b0ae
> >>>>
> >>>> compiled and restarted the VM with this kernel version
> >>>> (BTW: Of course I've always used the same .config for 
> >>>> all kernels I've build.). cf8d2c11cb77f129675478792122f50827e5b0ae
> >>>> is running fine.
> >>>>
> >>>> Thanks!
> >>>> Robert
> >>>>     
> >>>>         
> >>> Well, so the soft lockup issue seems NFS-related?
> >>> Trond, commit cf8d2c11cb77f129675478792122f50827e5b0ae seems to
> >>> be causing problems on some old kernels (See bisect below). Any idea why?
> >>>
> >>>
> >>>   
> >>>       
> >>>> On Wed, 21 Apr 2010 12:42:49 +0300, "Michael S. Tsirkin" <mst@redhat.com>
> >>>> wrote:
> >>>>     
> >>>>         
> >>>>> On Wed, Apr 21, 2010 at 01:23:12PM +0200, kernel wrote:
> >>>>>       
> >>>>>           
> >>>>>> So after the compiler was running hot I've now the following result:
> >>>>>>
> >>>>>> server10:/usr/src/linux # git bisect log 
> >>>>>> # bad: [74fca6a42863ffacaf7ba6f1936a9f228950f657] Linux 2.6.31
> >>>>>> # good: [07a2039b8eb0af4ff464efd3dfd95de5c02648c6] Linux 2.6.30
> >>>>>> git bisect start 'v2.6.31' 'v2.6.30'
> >>>>>> # good: [925d74ae717c9a12d3618eb4b36b9fb632e2cef3] V4L/DVB (11736):
> >>>>>> videobuf: modify return value of VIDIOC_REQBUFS ioctl
> >>>>>> git bisect good 925d74ae717c9a12d3618eb4b36b9fb632e2cef3
> >>>>>> # bad: [a380137900fca5c79e6daa9500bdb6ea5649188e] ixgbe: Fix device
> >>>>>> capabilities of 82599 single speed fiber NICs.
> >>>>>> git bisect bad a380137900fca5c79e6daa9500bdb6ea5649188e
> >>>>>> # good: [1dbb5765acc7a6fe4bc1957c001037cc9d02ae03] Staging: android:
> >>>>>> lowmemorykiller: fix up remaining checkpatch warnings
> >>>>>> git bisect good 1dbb5765acc7a6fe4bc1957c001037cc9d02ae03
> >>>>>> # good: [df36b439c5fedefe013d4449cb6a50d15e2f4d70] Merge branch
> >>>>>> 'for-2.6.31' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
> >>>>>> git bisect good df36b439c5fedefe013d4449cb6a50d15e2f4d70
> >>>>>> # bad: [a800faec1b21d7133b5f0c8c6dac593b7c4e118d] Merge branch
> >>>>>> 'for-linus'
> >>>>>> of git://www.jni.nu/cris
> >>>>>> git bisect bad a800faec1b21d7133b5f0c8c6dac593b7c4e118d
> >>>>>> # good: [ac1b7c378ef26fba6694d5f118fe7fc16fee2fe2] Merge
> >>>>>> git://git.infradead.org/mtd-2.6
> >>>>>> git bisect good ac1b7c378ef26fba6694d5f118fe7fc16fee2fe2
> >>>>>> # bad: [37c6dbe290c05023b47f52528e30ce51336b93eb] V4L/DVB (12091):
> >>>>>> gspca_sonixj: Add light frequency control
> >>>>>> git bisect bad 37c6dbe290c05023b47f52528e30ce51336b93eb
> >>>>>> # bad: [687d680985b1438360a9ba470ece8b57cd205c3b] Merge
> >>>>>> git://git.infradead.org/~dwmw2/iommu-2.6.31
> >>>>>> git bisect bad 687d680985b1438360a9ba470ece8b57cd205c3b
> >>>>>> # bad: [1053414068bad659479e6efa62a67403b8b1ec0a] Merge branch
> >>>>>> 'for-linus'
> >>>>>> of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6
> >>>>>> git bisect bad 1053414068bad659479e6efa62a67403b8b1ec0a
> >>>>>> # good: [b01b4babbf204443b5a846a7494546501614cefc] firewire: net: fix
> >>>>>> card
> >>>>>> driver reloading
> >>>>>> git bisect good b01b4babbf204443b5a846a7494546501614cefc
> >>>>>> # bad: [c02d7adf8c5429727a98bad1d039bccad4c61c50] NFSv4: Replace
> >>>>>> nfs4_path_walk() with VFS path lookup in a private namespace
> >>>>>> git bisect bad c02d7adf8c5429727a98bad1d039bccad4c61c50
> >>>>>> # good: [616511d039af402670de8500d0e24495113a9cab] VFS: Uninline the
> >>>>>> function put_mnt_ns()
> >>>>>> git bisect good 616511d039af402670de8500d0e24495113a9cab
> >>>>>> # good: [cf8d2c11cb77f129675478792122f50827e5b0ae] VFS: Add VFS helper
> >>>>>> functions for setting up private namespaces
> >>>>>> git bisect good cf8d2c11cb77f129675478792122f50827e5b0ae
> >>>>>>
> >>>>>>
> >>>>>> The last "git bisect good" prints out:
> >>>>>>
> >>>>>> server10:/usr/src/linux # git bisect good
> >>>>>> c02d7adf8c5429727a98bad1d039bccad4c61c50 is the first bad commit
> >>>>>> commit c02d7adf8c5429727a98bad1d039bccad4c61c50
> >>>>>> Author: Trond Myklebust <Trond.Myklebust@netapp.com>
> >>>>>> Date:   Mon Jun 22 15:09:14 2009 -0400
> >>>>>>
> >>>>>>     NFSv4: Replace nfs4_path_walk() with VFS path lookup in a private
> >>>>>> namespace
> >>>>>>     
> >>>>>>     As noted in the previous patch, the NFSv4 client mount code
> >>>>>>         
> >>>>>>             
> >>>> currently
> >>>>     
> >>>>         
> >>>>>>     has several limitations. If the mount path contains symlinks, or
> >>>>>>     referrals, or even if it just contains a '..', then the client code
> >>>>>>     in
> >>>>>>     nfs4_path_walk() will fail with an error.
> >>>>>>     
> >>>>>>     This patch replaces the nfs4_path_walk()-based lookup with a helper
> >>>>>>     function that sets up a private namespace to represent the
> >>>>>>         
> >>>>>>             
> >>>> namespace
> >>>>     
> >>>>         
> >>>>>> on the
> >>>>>>     server, then uses the ordinary VFS and NFS path lookup code to walk
> >>>>>> down the
> >>>>>>     mount path in that namespace.
> >>>>>>     
> >>>>>>     Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
> >>>>>>     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> >>>>>>
> >>>>>> :040000 040000 97a18818f26ab9a0987f157257eb6f399c3cc1cc
> >>>>>> 9ab6c712bb64f1349b5ac9f2020191abb5780ca0 M      fs
> >>>>>>
> >>>>>> Does this help you any further?
> >>>>>>
> >>>>>> Thanks!
> >>>>>> Robert
> >>>>>>         
> >>>>>>             
> >>>>> Looks suspiciously like some error in testing.
> >>>>> Could you pls retest and verify again that
> >>>>> cf8d2c11cb77f129675478792122f50827e5b0ae
> >>>>> is good and c02d7adf8c5429727a98bad1d039bccad4c61c50 is bad?
> >>>>>       
> >>>>>           

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