Hi Patrick, all but one of the xrootd threads are in the system calls, the one that is not in the system call is calling malloc with a valid parameter value, so I would say that the most likely scenarios are: 1) the malloc implementation you're using (Thread-Caching Malloc) is buggy 2) Athena is messing up the memory It is possible that it's xrootd that is causing the memory corruption, but knowing Athena, it's very unlikely. Cheers, Lukasz 2011/5/20 Patrick McGuigan <[log in to unmask]>: > Hello, > > A user's job seg-faulted when running in our system and produced the > attached stack trace. The information in the stack trace indicates that the > problems seemed to occur when the xrootd client was trying to allocate > additional memory (Thread 1). The code should have been using the client > libraries associated with the ROOT version packaged with ATLAS release. The > root version is labelled as "Version 5.26/00e 13 October 2010" > > I am curious if my diagnosis is correct, and if anyone has seen something > similar before? > > I reran the job on separate machine and it seemed to run fine. > > Regards, > > Patrick >