Messages in this thread |  | | Date | Tue, 13 Nov 2001 20:56:13 -0800 | From | Mike Kravetz <> | Subject | Re: [patch] scheduler cache affinity improvement for 2.4 kernels |
| |
On Thu, Nov 08, 2001 at 03:30:11PM +0100, Ingo Molnar wrote: > > i've attached a patch that fixes a long-time performance problem in the > Linux scheduler.
Just got back from holiday and saw this patch. I like the idea slowing down task dynamic priority modifications (the counter field). My only thought/concern would be in the case where a task with maximum dynamic priority (counter value) decides to use 'all' of its timeslice. In such a case, the task can not be preempted by another task (with the same static priority) until its entire timeslice is expired. In the current scheduler, I believe the task can be preempted after 1 timer tick. In practice, this shouldn't be an issue. However, it is something we may want to think about. One simple solution would be to update a tasks dynamic priority (counter value) more frequently it it is above its NICE_TO_TICKS value.
> (it would be nice if those people who suspect scalability problems in > their workloads, could further test/verify the effects this patch.)
I'll try to run it on my 'CPU intensive' version of the TPC-H behcnmark.
In addition, I have noted that this patch applies with minor modification to our MultiQueue scheduler, and should be a win in this environment also.
-- 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/
|  |