comments on late joyrides re: rt performance

[Deepak Saxena]

On Aug 07 2008, at 21:45, victor was caught saying:
> a few ms. I wondered about a change in
> preemption settings in the kernel that comes with the new OS.
> For some reason, 2263 seems slightly better than 2232, but I have
> to test more (I only updated it this evening)

As noted in #7603, the issues are most probably due to a major
scheduler rewrite from 2.6.22 -> 2.6.25. Please try the kernel 
I've pointed out in that trac.

> I will keep testing, but I expect that this will also have an impact
> on TamTam. I wonder if more 'aggressive' RT preemption patches
> (Ingo Molnar's ones come to mind) would be something worth
> considering. I am not sure whether OLPC would entertain the idea,
> but I would very much like to see the RT performance improved
> one way or another.

I'm very open to including Ingo's -rt patches in our kernel for 
a future release if we see that it improves overall responsiveness
of the system.

~Deepak


-- 
Deepak Saxena - Kernel Developer - dsaxena at laptop.org