From: Theodore Ts'o <tytso@mit.edu>
To: "Lukáš Czerner" <lczerner@redhat.com>
Cc: linux-ext4@vger.kernel.org, gharm@google.com
Subject: Re: [PATCH] ext4: Do not normalize request from fallocate
Date: Mon, 25 Mar 2013 10:44:08 -0400 [thread overview]
Message-ID: <20130325144408.GA4733@thunk.org> (raw)
In-Reply-To: <alpine.LFD.2.00.1303251420480.23176@localhost>
One of the things I've been thinking we need to add for some time is a
new field to the allocation_request structure which gives a hint to
mballoc about how much space we will eventually need (i.e., if we are
doing a 1GB fallocate, or if we know that we have 256megs worth of
dirty pages that we intend to write out in ext4_da_writepages, we
should tell mballoc that); this is different from how much space we
can actually use (i.e., 32,767 blocks given that's the maximum size we
can add in an uninitialized extents). If mballoc knew this, it could
reserve that much space as a per-file preallocation.
That might be the easist way to solve this particular issue.
- Ted
prev parent reply other threads:[~2013-03-25 14:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 15:50 [PATCH] ext4: Do not normalize request from fallocate Lukas Czerner
2013-03-21 16:03 ` Dmitry Monakhov
2013-03-22 17:10 ` Greg Harmon
2013-03-22 19:36 ` Theodore Ts'o
[not found] ` <514cb91d.8a48340a.33fd.ffff9fa3SMTPIN_ADDED_BROKEN@mx.google.com>
2013-03-22 22:19 ` Greg Harmon
2013-03-24 0:11 ` Theodore Ts'o
2013-03-24 2:42 ` Andreas Dilger
2013-03-25 10:09 ` Lukáš Czerner
2013-03-25 12:53 ` Theodore Ts'o
2013-03-25 13:26 ` Lukáš Czerner
2013-03-25 14:44 ` Theodore Ts'o [this message]
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