From: Dave Chinner <david@fromorbit.com>
To: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [RFC] fadvise: add more flags to provide a hint for block allocation
Date: Wed, 7 Mar 2012 11:51:30 +1100 [thread overview]
Message-ID: <20120307005130.GH3592@dastard> (raw)
In-Reply-To: <20120305125029.GA5121@gmail.com>
On Mon, Mar 05, 2012 at 08:50:29PM +0800, Zheng Liu wrote:
> Hi list,
>
> Block allocation is a key component of file system. Every file systems try to
> improve the performance with optimizing the block allocation of a file. But no
> matter what file system does, it just guesses what the user expects. Thus, it
> is not very accurate. fadvise(2) provides a method to let the user to give a
> hint to file system. However, until now, only few flags are provided. So we
> can provide more flags to tell file system how to allocate the blocks for a
> file.
>
> For example:
> we can add these flags into fadvise(2):
> FADV_ALLOC_READ_SEQ
fallocate()
> FADV_ALLOC_READ_RANDOM
Allocation can't be optimised as the read pattern cannot be defined.
> FADV_ALLOC_WRITE_ONCE
fallocate()
> FADV_ALLOC_WRITE_APPEND
chattr +a
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2012-03-07 0:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-05 12:50 [RFC] fadvise: add more flags to provide a hint for block allocation Zheng Liu
2012-03-05 19:48 ` Sunil Mushran
2012-03-06 2:35 ` Zheng Liu
2012-03-06 4:26 ` Sunil Mushran
2012-03-06 13:30 ` Zheng Liu
2012-03-06 8:27 ` Lukas Czerner
2012-03-06 13:56 ` Zheng Liu
2012-03-06 14:29 ` Lukas Czerner
2012-03-06 17:53 ` Sunil Mushran
2012-03-07 8:51 ` Lukas Czerner
2012-03-07 17:11 ` Ted Ts'o
2012-03-07 0:51 ` Dave Chinner [this message]
2012-03-07 4:14 ` Andreas Dilger
2012-03-07 5:02 ` Martin K. Petersen
2012-03-07 12:11 ` Dave Chinner
2012-03-08 4:23 ` Martin K. Petersen
2012-03-08 7:07 ` Dave Chinner
2012-03-08 17:01 ` Martin K. Petersen
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