[Pvfs2-developers] Error with concurrent opens

[Phil Carns]

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.

-Phil