Matt, That's definitely in line with what we're seeing. Not to beat a dead horse, and I am not a kernel hacker (so I apologize for any naivety), etc... but that's basically what led me to believe the CLOCK_PROCESS_CPUTIME_ID timers, top issues, and other CPU time monitoring may be relevant here.
Based on my rather high level understanding of CFS -- the big idea being that processes are scheduled based on their run time -- it seems plausible that a process that appears to be using no CPU time would continue to be prioritized by the scheduler. I'll leave any further analysis to someone who knows how these systems work. We have done a bit more testing on the 2.6.35 series kernels, with Ubuntu 10.10 (Maverick). So far we have not been able to reproduce this issue there. If we do I'll report back, but for now we are moving forward with migrating effected systems to Maverick. We're happy to assist with efforts to track this further, but I think we've documented most of what we've experienced. -- 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 [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
