Re: More on 2.2.18pre2aa2

From: Rik van Riel (riel@conectiva.com.br)
Date: Tue Sep 12 2000 - 03:11:59 EST


On Tue, 12 Sep 2000, David S. Miller wrote:
> From: Rik van Riel <riel@conectiva.com.br>
>
> I've just uploaded a new snapshot of my new VM for
> 2.4 to my home page, this version contains a
> wakeup_kswapd() function (copied from wakeup_bdflush)
> and should balance memory a bit better.
>
> How can drop_behind() work properly?
>
> You do not recompute the hash chain head for each decreasing
> 'index' in the main while loop, and thus you search potentially
> the wrong hash chain each time.
>
> Thus, you need to change:
>
> + page = __find_page_nolock(mapping, index, *hash);
>
> to something more like:
>
> + hash = page_hash(mapping, index);
> + page = __find_page_nolock(mapping, index, *hash);

Urghhh indeed. So /that's/ why drop_behind() didn't
seem to do its work ;)

Thanks for pointing out this obvious thinko. I hope
more people will take a look at my VM patch and try
to poke holes in it...

(until now, only 3 people seem to have bothered with
looking at the code in detail)

regards,

Rik

--
"What you're running that piece of shit Gnome?!?!"
       -- Miguel de Icaza, UKUUG 2000

http://www.conectiva.com/ http://www.surriel.com/

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