lkml.org 
[lkml]   [2007]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH][RSDL-mm 0/7] RSDL cpu scheduler for 2.6.21-rc3-mm2
Date
On Tuesday 13 March 2007 02:26, Linus Torvalds wrote:
> On Mon, 12 Mar 2007, Mike Galbraith wrote:
> > On Mon, 2007-03-12 at 22:23 +1100, Con Kolivas wrote:
> > > Mike the cpu is being proportioned out perfectly according to fairness
> > > as I mentioned in the prior email, yet X is getting the lower latency
> > > scheduling. I'm not sure within the bounds of fairness what more would
> > > you have happen to your liking with this test case?
> >
> > It has been said that "perfection is the enemy of good". The two
> > interactive tasks receiving 40% cpu while two niced background jobs
> > receive 60% may well be perfect, but it's damn sure not good.
>
> Well, the real problem is really "server that works on behalf of somebody
> else".
>
> X is just the worst *practical* example of this, since not only is it the
> most common such server, it's also a case where people see interactive
> issues really easily.
>
> And the problem is that a lot of clients actually end up doing *more* in
> the X server than they do themselves directly. Doing things like showing a
> line of text on the screen is a lot more expensive than just keeping track
> of that line of text, so you end up with the X server easily being marked
> as getting "too much" CPU time, and the clients as being starved for CPU
> time. And then you get bad interactive behaviour.
>
> So "good fairness" really should involve some notion of "work done for
> others". It's just not very easy to do..

Instead of assuming it's bad, have you tried RSDL for yourself? Mike is using
2 lame threads for his test case.

--
-ck
-
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: 2007-03-12 19:13    [W:0.239 / U:2.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site