[Pvfs2-developers] Error with concurrent opens

[Phil Carns]

I'm having a hard time thinking of anything specific that would have 
impacted this.  You could maybe try to narrow it down some by taking a 
diff of just the src/kernel/linux-2.6 directory and apply that to a 
2.7.1 tree to test and see if it is something specifically in the kernel 
module code.

-Phil

Bart Taylor wrote:
> 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 
> <mailto: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
> 
>