Re: [ANNOUNCE] RSDL completely fair starvation free interactive cpu scheduler

[Simon Arlott <simon@fire.lp0.eu>]

On 04/03/07 22:27, Con Kolivas wrote:
> On Monday 05 March 2007 09:19, Simon Arlott wrote:
>> If I run glxgears, thunderbird/firefox become really slow to
>> respond/display and cpu usage isn't even at 100%. I had thunderbird lagging
>> on keyboard character repeat earlier but can't reproduce that now even with
>> glxgears - however firefox lags really badly on keyboard input with
>> glxgears running.
> 
> Hi Simon
> 
> You're hitting a nasty udev bug here that is unrelated to the cpu scheduler 
Yes, I've already reported this.

> and almost certainly responsible for your bad behaviour. 
What? How do you make the leap from lockdep output on boot to my experience of 
slow interactive response?

> Also this patch was actually for 2.6.20 and you seem to have applied it to 
> 2.6.21-rc2. I haven't even checked that it cleanly applies to that kernel.

It doesn't, a one line fix from Ingo conflicts (and a comment that was changed).
7355690ead6d61f6344072ae61060f985060da29 [PATCH] sched: fix SMT scheduler bug
72fd4a35a824331d7a0f4168d7576502d95d34b3 [PATCH] Numerous fixes to kernel-doc info in source files.

I have reverted your patch and the laggy behaviour remains when running 
glxgears (in fact it seems a bit worse), I don't know about the thunderbird 
lag while typing since I can't easily reproduce it but I don't recall it ever 
happening before. So, your patch isn't the cause of a serious slowdown when 
running glxgears in the background (although it doesn't improve the situation 
much). It looks like it just slows down X in general rather than using much 
CPU.

-- 
Simon Arlott