[Pvfs2-developers] Error with concurrent opens

[Phil Carns]

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