I’m getting a segmentation fault at the beginning of my ROOT job (before any events are processed). When trying to track this down with gdb I run out of virtual memory:
What happens at the beginning of your job? Are many shared libs being loaded, creating many objects, etc? Check with vmstat or xosview what is going on.
[quote=“rdm”]What happens at the beginning of your job? Are many shared libs being loaded, creating many objects, etc? Check with vmstat or xosview what is going on.
/quote]
Actually, not that many things are loaded in the memory (the RAM jumps up by ~80 MB on a 1 GB RAM PC). The seg. fault is pretty much reproducible (I’ve run the code about 10 times, I think I failed to get a crash only once ), even though it sometimes occurs a little later (after a few events have been processed).
This may be a rare problem in my code: I’ve run/submitted 62 jobs (a total of 3.5 M events), 61 jobs went through fine, this one refuses to cooperate. Or, it could be a problem with the input file. The problem is that when I try to track this down with gdb I run out of memory (gdb gets killed, at one instance my Linux box had to be rebooted…). So, I’m out of ideas at this point…
OK, off-topic, but, I have noticed this too: gdb needing excessive amounts of memory. Current versions of D0 code come with an older version of gdb, so you could try getting a newer one (how about “unsetup gdb”, depending on what system you’re on). It worked for me (RH Linux 7.3).