Re: [PATCH] Optimize out pte_chain take three

[Rik van Riel <riel@conectiva.com.br>]

On Thu, 11 Jul 2002, Andrew Morton wrote:
> Rik van Riel wrote:
> > ...
> > > useful pagecache and swapping everything out.  Our kernels have
> > > O_STREAMING because of this.   It simply removes as much pagecache
> > > as it can, each time ->nrpages reaches 256.  It's rather effective.
> >
> > Now why does that remind me of drop-behind ? ;)
>
> I looked at 2.4-ac as well.  Seems that the dropbehind there only
> addresses reads?

It should also work on linear writes.


> I suspect the best fix here is to not have dirty or writeback
> pagecache pages on the LRU at all.  Throttle on memory coming
> reclaimable, put the pages back on the LRU when they're clean,
> etc.  As we have often discussed.  Big change.

That just doesn't make sense, if you don't put the dirty pages
on the LRU then what incentive _do_ you have to write them out ?

Will you start writing them out once you run out of clean pages ?

Will you reclaim all glibc mapped pages before writing out dirty
pages ?

If the throttling is wrong, I propose we fix the trottling.

regards,

Rik
-- 
Bravely reimplemented by the knights who say "NIH".

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

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