Re: [REPORT] 2.6.21 vs. 2.6.21-sd046 vs. 2.6.21-CFSv7

[Con Kolivas <kernel@kolivas.org>]

On Tuesday 01 May 2007 05:29, Bill Davidsen wrote:
> System: Intel 6600 Core2duo, 2GB RAM, X nice 0 for all tests, display
> using i945G framebuffer

Bill thanks for testing.
>
> Test: playing a 'toon with mplayer while kernel build -j20 running.

Umm I don't think make -j20 is a realistic load on 2 cores. Not only does it 
raise your load to 20 but your I/O bandwidth will even be struggling. If 
video playback was to be smooth at that size a load it would suggest some 
serious unfairness. I'm not just pushing the fairness barrow here; I mean it 
would need to be really really unfair unless your combined X and video 
playback cpu combined added up to less than 1/20th of your total cpu power 
(which is possible but I kinda doubt it). Do you really use make -j20 to 
build regularly?

> Tuning: not yet, all scheduler parameters were default
>
> Result: base 2.6.21 showed some pauses and after the pause the sound got
> louder for a short time (<500ms). With sd-0.46 the playback had many
> glitches and finally just stopped with the display looping on a small
> number of frames and no sound. The skips were repeatable, the hang was
> only two of five runs, I didn't let them go until the make finished
> (todo list) but killed the mplayer after 10-15 sec. No glitches observed
> with cfsv7, I thought I saw one but repeating with granularity set to
> 500000 and then with no make running convinced me that it's just a
> crappy piece of animation at that point.

I did notice on your followup email that nice +10 of the 20 makes fixed the 
playback which sounds pretty good.

> I ran glxgears, again sd-0.46 had frequent pauses and uneven fps
> reported. Stock 2.6.21 had a visible pause when the frame rate was
> output, otherwise minimal pauses. CFSv7 appeared smooth at about 250 fps.

I assume you mean glxgears when you're running make -j20 again here.

> All tests gave acceptable typing echo, it seems that X is getting enough
> time at that load to echo without major issues.

That's nice; shows stability under load.

> I will be doing tests with server load later this week, have to add disk
> for the database.

Great.

> Hope this initial report is useful, I may be able to update ctxbench
> later today and try that.

Also good.

-- 
-ck