Bugs item #3267963, was opened at 2011-04-01 23:07 Message generated for change (Settings changed) made by metan You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=103382&aid=3267963&group_id=3382
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Testcases Group: Scheduler >Status: Open Resolution: None Priority: 5 Private: No Submitted By: Mike Kravetz (mkravetz) Assigned to: Cyril Hrubis (metan) Summary: process_stress infinite loop Initial Comment: ./testcases/kernel/sched/process_stress/process -b10 -d2 can go into an infinite loop. The test creates a tree of processes. Each process will send a message (msgsnd, queue up) to all of its siblings. After sending messages, it will then read (msgrcv) from its siblings. The issue/bug is that on a large systems with lots of cores/processors (64 cores in my case) it is possible for many processes to be sending messages in parallel. All before any/many processes have started reading/receiving messages. This will result in the message queue filling up before the processes start emptying (msgrcv) the queue. Once the queue is full, processes retry forever hoping someone will drain. But, everyone is sending 'at once'. This 'works' in environments with lower core/processor counts as processes are able to queue up request and drain some in the same time slice. To test/verify you can add a 'sleep(1)' to the testcase after it does all the sends, and before doing any receives. I ran this on a small (4 processor) system and it failed (ran forever) in the same manner as it did on the large system. ---------------------------------------------------------------------- Comment By: Cyril Hrubis (metan) Date: 2011-04-06 18:30 Message: Thanks for the detailed report. We've seen similar symptoms while testing SUSE linux here in suse. I'll look at the code. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=103382&aid=3267963&group_id=3382 ------------------------------------------------------------------------------ Benefiting from Server Virtualization: Beyond Initial Workload Consolidation -- Increasing the use of server virtualization is a top priority.Virtualization can reduce costs, simplify management, and improve application availability and disaster protection. Learn more about boosting the value of server virtualization. http://p.sf.net/sfu/vmware-sfdev2dev _______________________________________________ Ltp-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ltp-list
