Messages in this thread | | | Date | Fri, 2 May 2008 21:28:03 +0400 | From | Oleg Nesterov <> | Subject | Re: CPU POSIX timers livelock |
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On 05/02, Bj?rn Steinbrink wrote: > > Hm, I have some message in that thread from April they don't seem to be > on lkml.org nor in the bugzilla though. Oh well, I can send you an mbox > of that thread in a private mail, just let me know if you want that.
Me too please ;)
Please note there is a related problem if we have a single thread but a lot of timers attached to this thread. If the signal is ignored, each timer should be re-armed, this all can consume >= 1/HZ CPU time. We have "maxfire = 20" in check_thread_timers/check_process_timers to prevent this, but it is just a workaround. And it is a bit silly to just waste the CPU if the signal is ignored, arm_timer() is heavy and doesn't scale well.
However, I have already forgot this code, perhaps I missed something, and at least maxfire does help.
Oleg.
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