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Date: Wed, 21 Mar 2001 16:54:48 -0300 (BRST)
From: Rik van Riel <riel@conectiva.com.br>
To: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Josh Grebe <squash@primary.net>, linux-kernel@vger.kernel.org,
        Manfred Spraul <manfred@colorfullife.com>
Subject: Re: Question about memory usage in 2.4 vs 2.2
In-Reply-To: <20010321141626.A3621@cs.cmu.edu>
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On Wed, 21 Mar 2001, Jan Harkes wrote:

> I've been thinking about this a bit and one possible solution would be
> to significantly lower the cost of prune_icache by removing the
> sync_all_inodes and only let it prune inodes that do not have any
> mappings associated with them. Then it might become possible to call
> it more frequently, like every time we hit do_try_free_pages.

Marcelo and me have been looking at this issue too, and have
come to almost the same conclusion as you, with one small
change.

We -need- to have a way to trigger the writeout of dirty
inodes under memory pressure. Imagine doing 'chown -R' on
a huge tree on a low-memory box; you'd end up with zillions
of dirty inodes in memory with no way to free them.

Now if prune_icache would write all the dirty inodes without
data pages to disk automatically, we'd have this issue fixed
and we'll be able to make a much more efficient prune_icache.

Anybody willing to give it a shot ?

regards,

Rik
--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

		http://www.surriel.com/
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