lkml.org 
[lkml]   [2003]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Using O(1) scheduler with 600 processes.
From
Date
On Thu, 2003-01-23 at 20:05, mgross wrote:
> You should definitely give it a try.
>
> However; boosts in Oracle throughput by going to the O(1) scheduler may end
> up being dependent on your I/O setup.
>
> I was helping out with a TPCC benchmark effort last fall for Itanium Oracle
> through put on Red Hat AS. For the longest time the guys with the big iron
> hardware would not move to the newer kernels with the O(1) scheduler. They
> had a silly rule of only accepting changes that improved TPCC throughput.
> (oh, this work was on 4-way Itanium 2's with 32Gig of ram, and a large number
> of clarion fiber channel disk array towers)

We've got LSI, so it's very similar.

> Anyway, for the longest time the old 2.4.18 kernel with the 4/10/04 ia-64
> patch was 10% better than the a kernel with O(1) scheduler. I never quite
> figured out what the problem was. I think the difference was in the way
> Oracle likes to be on a Round Robbin scheduler, and the O(1) scheduler tended
> to get unlucky more often than the old scheduler, for those drive arrays.
>
> However; when we updated the clarion towers to have more drives and to 18K
> RPM drives from the 15K drives, all of a sudden the O(1) scheduler beat the
> the old scheduler.

Well, if I could get a clean patch against 2.4.20, or possibly some help
fixing the one I do have, thanks to Ingo, then we'd have a straight
O(1) sched for 2.4.20. I tried merging the patch that Ingo gave me, and
everything seems OK, but I don't have any menu selection for O(1) stuff
in the kernel config.(0 and 100 priority bits)

So I can't tell if it's enabled.


> Your milage will vary.
>
> Give it a try.
>
> --mgross
>

I agree. In the interest of time, I may have to forego O(1), but maybe
I'll get lucky. :) *hint*hint* :)

TIA

--
GrandMasterLee
-
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/

\
 
 \ /
  Last update: 2005-03-22 13:32    [W:0.051 / U:0.604 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site