From: Andreas Dilger <adilger@sun.com>
To: Mingming Cao <cmm@us.ibm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
tytso@mit.edu, linux-ext4@vger.kernel.org
Subject: Re: [PATCH] ext4: zero out small extents when writing to prealloc area.
Date: Tue, 04 Mar 2008 23:45:17 -0700 [thread overview]
Message-ID: <20080305064517.GB3616@webber.adilger.int> (raw)
In-Reply-To: <1204678288.3605.15.camel@localhost.localdomain>
On Mar 04, 2008 16:51 -0800, Mingming Cao wrote:
> On Tue, 2008-03-04 at 18:16 +0530, Aneesh Kumar K.V wrote:
> > + /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
> > + if (ee_len <= 2*EXT4_EXT_ZERO_LEN) {
>
> Hmm, here this is range is extended to 2*EXT4_EXT_ZERO_LEN? I am a
> little more biased to keep the threshold constant as EXT4_EXT_ZERO_LEN
> around all places...
I initially thoguht this also, but it makes sense. If the extent is
<= 2x EXT4_EXT_ZERO_LEN and it is split anywhere then the resulting
parts will be < EXT4_EXT_ZERO_LEN themselves, unless split is very
close to one edge. Even then it is better to keep a single initialized
extent instead of 3 different ones.
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.
prev parent reply other threads:[~2008-03-05 6:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-04 12:46 [PATCH] ext4: zero out small extents when writing to prealloc area Aneesh Kumar K.V
2008-03-05 0:51 ` Mingming Cao
2008-03-05 6:45 ` Andreas Dilger [this message]
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