Messages in this thread | | | Subject | Re: Resent: BUG in RT 45-01 when RT program dumps core | From | Steven Rostedt <> | Date | Thu, 19 May 2005 07:56:03 -0400 |
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On Thu, 2005-05-19 at 08:36 +0200, kus Kusche Klaus wrote: > Quoting my mail from Apr 11th (received no response up to now):
Sorry, I must have missed it, I try to keep up on all mail associated to Ingo's RT kernel. Including Ingo on the list is the right thing to do.
> > When a process running with RT priority dumps core, > > I get the following BUG: > > > > Apr 11 13:44:23 OF455 kern.err kernel: BUG: rtc2:833 RT task > > yield()-ing!
This is a check that we have to flag when a RT task calls yield. This in itself may not really be a bug, but it can be. There's places in the kernel that call yield to wait for a bit to clear or a lock to become unlock (doesn't grab it directly to prevent deadlocking). This may be OK with non RT tasks, since other tasks will get a chance to run. But with RT tasks, a yield won't yield to any task with less priority than the RT task. So if the RT task is yielding to let a lower priority task do something it needs, it will in effect deadlock the system for all tasks lower in priority than itself.
> This is still absolutely reproducable, in RT 7.47-01, > with slight variations in the stack trace. > > Is this something to worry about?
I'll take a look into it.
Ingo,
Did you get my patch to fix the kstop_machine yielding problem?
-- Steve
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