From: Andy Whitcroft <apw@shadowen.org>
To: "Jörn Engel" <joern@logfs.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: Page scan keeps touching kernel text pages
Date: Mon, 25 Feb 2008 15:07:24 +0000 [thread overview]
Message-ID: <20080225150724.GF2604@shadowen.org> (raw)
In-Reply-To: <20080224144710.GD31293@lazybastard.org>
On Sun, Feb 24, 2008 at 03:47:11PM +0100, Jorn Engel wrote:
> While tracking down some unrelated bug I noticed that shrink_page_list()
> keeps testing very low page numbers (aka kernel text) until deciding
> that the page lacks a mapping and cannot get freed. Looks like a waste
> of cpu and cachelines to me.
>
> Is there a better reason for this behaviour than lack of a patch?
shrink_page_list() would be expected to be passed pages pulled from
the active or inactive lists via isolate_lru_pages()? I would not have
expected to find the kernel text on the LRU and therefore not expect to
see it passed to shrink_page_list()?
I would expect to find pages below the kernel text as real pages, and
potentially on the LRU on some architectures. Which architecture are
you seeing this? Which zones do the pages belong?
-apw
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next prev parent reply other threads:[~2008-02-25 15:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-24 14:47 Page scan keeps touching kernel text pages Jörn Engel
2008-02-25 15:07 ` Andy Whitcroft [this message]
2008-02-25 15:15 ` Jörn Engel
2008-02-25 17:35 ` Jörn Engel
2008-02-25 17:48 ` Dave Hansen
2008-02-25 18:53 ` Jörn Engel
2008-02-25 19:21 ` Andy Whitcroft
2008-02-25 19:46 ` Dave McCracken
2008-02-25 20:38 ` Jörn Engel
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