Messages in this thread | | | Date | Wed, 21 May 2003 22:46:15 +0200 | From | Mike Galbraith <> | Subject | Re: web page on O(1) scheduler |
| |
At 10:56 AM 5/21/2003 -0700, David Mosberger wrote: > >>>>> On Wed, 21 May 2003 11:26:31 +0200, Mike Galbraith <efault@gmx.de> > said: > > Mike> The page mentions persistent starvation. My own explorations > Mike> of this issue indicate that the primary source is always > Mike> selecting the highest priority queue. > >My working assumption is that the problem is a bug with the dynamic >prioritization. The task receiving the signals calls sleep() after >handling a signal and hence it's dynamic priority should end up higher >than the priority of the task sending signals (since the sender never >relinquishes the CPU voluntarily).
The only thing that matters is how much you sleep vs run, so yes, it should have a higher priority unless that handling is heavy on cpu. If it doesn't, then you have to have a different problem, because the dynamic priority portion of the scheduler is dead simple. The only way I can imagine that priority could end up lower than expected is heavyweight interrupt load, or spinning out of control.
>However, I haven't actually had time to look at the relevant code, so >I may be missing something. If you understand the issue better, >please explain to me why this isn't a dynamic priority issue.
I just saw your other post regarding the web page. Now that I know that there's a detailed description in there somewhere, I'll go read it and see if any of what I've gleaned from crawling around the scheduler code is useful. I thought you might be encountering the same kind of generic starvation I've seen. Ergo, the simple diag patch.
-Mike
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |