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Message-ID: <2c0942db0805070808t663eafffic5e78c9d1ba8bc68@mail.gmail.com>
Date: Wed, 7 May 2008 08:08:09 -0700
From: "Ray Lee" <ray-lk@madrabbit.org>
To: "Matthew Wilcox" <matthew@wil.cx>
Subject: Re: It's time to hack on dentry_stat?
Cc: "rae l" <crquan@gmail.com>, linux-fsdevel@vger.kernel.org,
       linux-kernel@vger.kernel.org
In-Reply-To: <20080507145116.GV19219@parisc-linux.org>
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	 <20080507145116.GV19219@parisc-linux.org>
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On Wed, May 7, 2008 at 7:51 AM, Matthew Wilcox <matthew@wil.cx> wrote:
> On Wed, May 07, 2008 at 10:26:58PM +0800, rae l wrote:
>  > I have noticed that struct dentry_stat_t dentry_stat is a struct with
>  > six fields,
>  > but only 2 of them are used, other 4 have never been used since v2.6.11,
>  >
>  > from include/linux/dcache.h:
>  >
>  > struct dentry_stat_t {
>  >         int nr_dentry;
>  >         int nr_unused;
>  >         int age_limit;          /* age in seconds */
>  >         int want_pages;         /* pages requested by system */
>  >         int dummy[2];
>  > };
>
>  You have to not break:
>
>  $ cat /proc/sys/fs/dentry-state
>  122104  115846  45      0       0       0

One could hardcode the output of the last three (four?) fields, yes?
Slightly grotty, but if it comes with a decent memory savings...