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From: Alberich de megres <alberich2k5@gmail.com>
To: Andreas Dilger <adilger@sun.com>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: ext4 allocator
Date: Mon, 25 Jan 2010 23:44:08 +0100	[thread overview]
Message-ID: <12d708831001251444y5eaad686we802e3c0d2af34ae@mail.gmail.com> (raw)
In-Reply-To: <E906D423-D80C-4BDC-BAF3-92BAB309A1E1@sun.com>

Wow, how newbie i am...

Thanks man!!


On Mon, Jan 25, 2010 at 10:37 PM, Andreas Dilger <adilger@sun.com> wrote:
> On 2010-01-25, at 14:14, Alberich de megres wrote:
>>
>> I'm studyng ext4 code, and i got a doubt on a situation:
>>
>> Supposing a 4K page size, and a fs with 8K.. when we are filling page
>> info,:
>>
>> { 4K page }{ 4K page }{ 4K page }{ 4K page }
>> [   group 0 bitmap   ][   group 0 buddy    ]
>>
>> Clearly bitmap and buddy info don't fits on a single page, but e4b
>> structure saves only one page address.
>>
>> How mb allocator menages this situation??
>
>
> ext4, and the Linux VM/block layer in general, do not support disk block
> size larger than the page size.  That has been a restriction for a long time
> already, and there have been various patches/proposals to fix that, but
> nothing that ever made it into the mainline kernel.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Sr. Staff Engineer, Lustre Group
> Sun Microsystems of Canada, Inc.
>
>
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      reply	other threads:[~2010-01-25 22:44 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-25 21:14 ext4 allocator Alberich de megres
2010-01-25 21:37 ` Andreas Dilger
2010-01-25 22:44   ` Alberich de megres [this message]

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