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Date: Sun, 16 Dec 2012 02:15:08 +0000
From: Eric Wong <normalperson@yhbt.net>
To: xtu4 <xiaobing.tu@intel.com>
Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org,
        linux-mm@kvack.org, di.zhang@intel.com
Subject: Re: resend--[PATCH]  improve read ahead in kernel
Message-ID: <20121216021508.GA3629@dcvr.yhbt.net>
References: <50C4B4E7.60601@intel.com>
 <50C6AB45.606@intel.com>
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xtu4 <xiaobing.tu@intel.com> wrote:
> resend it, due to format error
> 
> Subject: [PATCH] when system in low memory scenario, imaging there is a mp3
>  play, ora video play, we need to read mp3 or video file
>  from memory to page cache,but when system lack of memory,
>  page cache of mp3 or video file will be reclaimed.once read
>  in memory, then reclaimed, it will cause audio or video
>  glitch,and it will increase the io operation at the same
>  time.

To me, this basically describes how POSIX_FADV_NOREUSE should work.
I would like to have this ability via fadvise (and not CONFIG_).

Also, I think your patch has too many #ifdefs to be accepted.