Re: [RFC][PATCH] the proposal of improve page reclaim by throttle

From: minchan Kim
Date: Wed Feb 20 2008 - 04:49:21 EST


On Feb 20, 2008 6:24 PM, KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
> Hi Kim-san
>
> Do you adjust hackbench parameter?
> my parameter adjust my test machine(8GB mem),
> if unchanged, maybe doesn't works it because lack memory.

I already adjusted it. :-)
But, In my desktop, I couldn't make to consune my swap device above
half. (My swap device is 512M size)
Because my kernel almost was hang before happening many swapping.
Perhaps, it might be a not hang. However, Although I wait a very long
time, My box don't have a any response.
I will try do it more.

> > I am a many interested in your patch. so I want to test it with exact
> > same method as you did.
> > I will test it in embedded environment(ARM 920T, 32M ram) and my
> > desktop machine.(Core2Duo 2.2G, 2G ram)
>
> Hm
> I don't have embedded test machine.
> but I can desktop.
> I will test it about weekend.
> if you don't mind, could you please send me .config file
> and tell me your test kernel version?

I mean I will test your patch by myself.
Because I already have a embedded board and Desktop.

> Thanks, interesting report.
>
>
> > I guess this patch won't be efficient in embedded environment.
> > Since many embedded board just have one processor and don't have any
> > swap device.
>
> reclaim conflict rarely happened on UP.
> thus, my patch expect no improvement.

I agree with you.

> but (of course) I will fix regression.

I didn't say your patch had a regression.
What I mean is just that I am concern about it.
Actually, Many VM guys is working on server environment.
They didn't try to do performance test in embedde system.
and that patch was submitted in mainline.

Actually, I am concern about it.

> > So, How do I evaluate following field as you did ?
> >
> > * elapse (what do you mean it ??)
> > * major fault
>
> /usr/bin/time command output that.
>
>
> > * max parallel reclaim tasks:
> > * max consumption time of
> > try_to_free_pages():
>
> sorry, I inserted debug code to my patch at that time.
>

Could you send me that debug code ?
If you will send it to me, I will test it my environment (ARM-920T, Core2Duo).
And I will report test result.

--
Thanks,
barrios
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