Matt, Still no way to reproduce deterministically. I've just been running variations of the test I posted above, writing to /dev/null and setting timer signals. At some point the tests/system start hanging.
irqbalance is not running on any of the test instances that are hanging (it appears to be started automatically on the Maverick ami, but that node is happy). I believe we've run it in the past on some nodes. I'll check if we there are any that are hanging that also have irqbalance started at boot. I know that I personally started irqbalance on some nodes after boot to see if that would fix things (to no avail), but it wasn't started at boot. If we don't have any running nodes with irqbalance I'll have to reboot a node and start over, which may take some time. -- You received this bug notification because you are a member of Ubuntu Bugs, which is a direct subscriber. https://bugs.launchpad.net/bugs/708920 Title: Strange 'fork/clone' blocking behavior under high cpu usage on EC2 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
