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

[Bill Davidsen <davidsen@tmr.com>]

Con Kolivas wrote:
> 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?
>
>   
Yes, this is a compile and file server, I frequently build a raft of 
kernels when a security patch comes out. There doesn't seem to be an i/o 
issue, with 2GB RAM and RAID5 over a SATA array I have enough, but 
honestly the disk activity is minimal, even with a single drive.
> > 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.
>
>   
Yes, I can get around the load doing that.
> > 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.
>   
Of course. ;-)

--
bill davidsen <davidsen@tmr.com>
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979

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