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From: cai <junjiec@gmail.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][fat] use mpage_readpage when cluster size is page-alignment
Date: Thu, 29 Dec 2005 17:52:40 +0900	[thread overview]
Message-ID: <43B3A3D8.6050605@gmail.com> (raw)
In-Reply-To: <84144f020512290006x71d2c245s5e148fae15720d59@mail.gmail.com>

hi,

>I am not sure I am following you. Shouldn't do_mpage_readpage work for
>all adjacent blocks regardless of whether block size is page-aligned
>or not? What's is the performance problem you're thinking of?
>
>                            Pekka
>
>  
>
no, not block size but cluster size
as you know, in FAT, file is organized in clusters
and one cluster could have N blocks(sectors).
so if cluster size is not page-aligned,
a page may live in non-adjacent blocks, and
do_mpage_readpage has to fall back to block_read_full_page
in this case.

thanks.
                                   junjie


  reply	other threads:[~2005-12-29  8:49 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-12-28  7:56 [RFC][fat] use mpage_readpage when cluster size is page-alignment junjie cai
     [not found] ` <2cd57c900512280040g594ba003y@mail.gmail.com>
2005-12-28  9:36   ` junjie cai
2005-12-28 12:57 ` OGAWA Hirofumi
2005-12-29  6:38   ` cai
2005-12-29  8:06     ` Pekka Enberg
2005-12-29  8:52       ` cai [this message]
2005-12-29  9:12         ` Pekka J Enberg
2005-12-29  9:19     ` OGAWA Hirofumi
2005-12-29 10:24       ` cai

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