Date: Thu, 25 May 2006 09:23:11 -0700
From: Andrew Morton <akpm@osdl.org>
To: Wu Fengguang <wfg@mail.ustc.edu.cn>
Cc: linux-kernel@vger.kernel.org, wfg@mail.ustc.edu.cn
Subject: Re: [PATCH 04/33] readahead: page flag PG_readahead
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Wu Fengguang <wfg@mail.ustc.edu.cn> wrote:
>
> An new page flag PG_readahead is introduced as a look-ahead mark, which
> reminds the caller to give the adaptive read-ahead logic a chance to do
> read-ahead ahead of time for I/O pipelining.
> 
> It roughly corresponds to `ahead_start' of the stock read-ahead logic.
> 

This isn't a very revealing description of what this flag does.

> +#define __SetPageReadahead(page) __set_bit(PG_readahead, &(page)->flags)

uh-oh.  This is extremly risky.  Needs extensive justification, please.
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