Re: Ten percent test

Gene Heskett
2007-04-07T18:24:09Z

On Saturday 07 April 2007, Ingo Molnar wrote:
>* Gene Heskett <gene.heskett@gmail.com> wrote:
>> To be expected, there are after all, only so many cpu cycles to go
>> around. Here I sit, running 2.6.21-rc6 ATM, and since there is not an
>> SD patch that applies cleanly to rc6, I am back to typing half or more
>> of a sentence blind while I answer a posting such as this because of x
>> starvation while kmail is sorting incoming stuff.
>
>it would be really nice to analyze this. Does the latest -rt patch boot
>on your box so that we could trace this regression? (I can send you a
>standalone tracing patch if it doesnt.) IIRC you reported that one of
>the early patches from Mike made your system behave good (but still not
>as good as SD) - it would be nice to try a later patch too.

Yes it would be Ingo, but so far, none of the recent -rt patches has
booted on this machine, the last one I tried a few days ago failing to
find /dev/root, whatever the heck that is.

FWIW, I gave up on the rt stuffs 6 months or more ago when the regressions
I was reporting weren't ever acknowledged. I don't enjoy sitting through
all these e2fsk's during the reboot just to have things I normally run in
the background die, like tvtime, sitting there with some news channel
muttering along in the background. I was even ignored when I suggested
it might be a dma problem, which I still think it could be.

Nevertheless, the patch you sent is building as I type, intermittently
when the screen deigns to update so I can fix the spelling etc.

>basically, the current unfairness in the scheduler should be solved, one
>way or another. Good testcases were posted and there's progress.
>
>> (who the hell runs a 'make -j 200' or 50 while(1)'s in the real world?
>
>not many - and i dont think Mike tested any of these - Mike tested
>pretty low make -j values (Mike, can you confirm?).
>
>(I personally routinely run 'make -j 200' build jobs on my box [because
> it's the central server of a build cluster and high parallelism is
> needed to overcome network latencies], but i'm pretty special in that
> regard and i didnt use that workload as a test against any of these
> schedulers.)

And I'd wager a cool one that you don't gain more than a second or so in
compile time between a make -j8 and a make -j200 unless your network is a
pair of tomato juice cans & some string. Again, to me, the network thing
is not something that's present in an everyday users environment. My
drives are all here and now, on pata-133 interfaces.

> Ingo

--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If you would keep a secret from an enemy, tell it not to a friend.