[Pvfs2-developers] Error with concurrent opens

[Bart Taylor]

I ran the test the same way you mentioned - outside of the LTP framework -
and still had the problem. I have applied the patch that fixed the rename06
test as well as the kernel buffer overflow fix from a few days ago and still
have the problem.

I did a CVS export of head this morning and used the same configure and
build as last time. I ran the open file test against a file system created
from head and against a 271 file system (with some recent patches) and both
tests succeed, so it seems like the fix is somewhere between the 271 release
and head, but I am not sure where. Do you have an idea where it might be
lurking?

Bart.



On Fri, Jul 25, 2008 at 7:16 AM, Phil Carns <carns at mcs.anl.gov> wrote:

> Phil Carns wrote:
>
>> Bart Taylor wrote:
>>
>>> I am having a problem with an LTP test from the 20080630 set of LTP
>>> tests. The
>>> 'openfile01' test does 10 threaded opens of 10 files. It is attached in
>>> case you
>>> need a copy. The test completes successfully, but an 'ls' command
>>> immediately
>>> after that  hangs and cannot be killed. Eventually the node hangs as
>>> well. Any
>>> command that touches the file system will trigger the problem.
>>>
>>> We also tried this with the 2.7.1 release tarball and see the same
>>> problem. A
>>> single node file system running RHEL4 and a 2.6.9-67 kernel. The client
>>> was on
>>> the same node.
>>>
>>> Here is the configure line used:
>>>
>>>   ./configure --with-kernel=/lib/modules/`uname -r`/build
>>>
>>> and how the client was started:
>>>
>>>   ./pvfs2-client -p ./pvfs2-client-core
>>>
>>> The fs.conf file is attached.
>>>
>>> The client debug mask was set to 'all', and /proc/sys/pvfs2/debug had a
>>> value of
>>> 32767. But once the 'ls' command was issued, there were no log messages.
>>>
>>> Does anyone else see this error?
>>>
>>> Bart.
>>>
>>
>> Are you able to reproduce this running openfile by itself after a fresh
>> boot?  It looks like openfile operates on a file in the current working
>> directory, so I have been trying to run it like this:
>>
>> <mount pvfs2 on /mnt/pvfs2>
>> cd /mnt/pvfs2
>> ~/openfile -f10 -t10
>> ls -alh
>>
>> So far I haven't had any trouble with that particular combination.  I'm
>> running it on a centos4 box with a very similar kernel.  The openfile tests
>> looks fairly innocent- with those arguments each of 10 separate threads open
>> the same single file 10 times (for a total of 100 file descriptors open to
>> the same file) if I understand correctly.
>>
>> If I try to run a full LTP test, however, I do have other problems.  In
>> particular the rename06 test hangs.  I can trigger that one by itself as
>> follows:
>>
>> export TMPDIR=/mnt/pvfs2
>> ~/rename06
>>
>> The same suite of tests runs fine on a 2.6.24 kernel and a trunk build of
>> PVFS.  I'm not sure yet if the difference is between pvfs versions or
>> between kernel versions.
>>
>
> The rename06 test passes with pvfs trunk; I think that particular problem
> has already been fixed.  I still haven't figured out why openfile01 would be
> a problem, though.
>
> -Phil
>
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