If I run "bin/manta -bench 10 10 -imagedisplay null -np 2" on an Altix, the program exits in a bad way, complaining of "ERROR: Incorrect Phase" and then telling me that "Thread 'idle or main'" got a SIGSEGV.  If I run this again with the LD_ASSUME_KERNEL environment variable set to "2.4.19" it exits cleanly.

SGI's documentation says that this behavior is indicative of an application "which depends on behaviors in which the LinuxThreads implementation deviates from the POSIX standard".  The LD_ASSUME_KERNEL environment variable forces the application to use the old LinuxThreads implementation rather than NPTL (Native POSIX Thread Library).  I think the new thread package was included with ProPack 3.0 on the Altix.  You might not see this problem on your Altix if it is running an earlier version of the system software.

I thought I had tried this earlier and didn't have this problem, but as it is just an environment variable, now I'm wondering if this has always been broken this way.  Is anyone aware of any changes in the pthread code made over the last week or so that may have changed this behavior?  Does anyone feel more qualified than I do about mucking around in this code and trying to understand what goes on when the program exits?

            Rocky