Message-ID: <8783be6604062408493cacc648@mail.gmail.com>
Date: Thu, 24 Jun 2004 08:49:09 -0700
From: Ross Biro <ross.biro@gmail.com>
To: David Ashley <dash@xdr.com>
Subject: Re: Cached memory never gets released
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <200406241448.i5OEmK60025648@xdr.com>
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On Thu, 24 Jun 2004 07:48:20 -0700, David Ashley <dash@xdr.com> wrote:

> So we're snowballing but I don't know what mechanism is supposed to actually
> free the cached pages when the system is low on memory. Any advice would
> be welcome.
> 

You may want to examine /proc/meminfo, /proc/slabinfo, and the output
of sysrq-m.

mm/vmscan.c (kswapd) is responsible for freeing most memory.  The
routine you are probably most interested in is shrink_cache.

I would check to make sure that the pages in the icache are backed by
a mapping and if so, that they are clean.   If either of those two
conditions are not met, then the page cannot be thrown away.
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