From: Christoph Hellwig <hch@infradead.org>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>,
Dave Chinner <david@fromorbit.com>,
linux-xfs@vger.kernel.org
Subject: Re: Question on slow fallocate
Date: Tue, 27 Jun 2023 21:56:49 -0700 [thread overview]
Message-ID: <ZJu9kb14LcXgGmjA@infradead.org> (raw)
In-Reply-To: <82b74cbc-8a1d-6b6f-fa2f-5f120d958dad@sandeen.net>
On Tue, Jun 27, 2023 at 11:12:01AM -0500, Eric Sandeen wrote:
> Ok, but what is the reason for zeroing out the blocks prior to them being
> written with real data? I'm wondering what the core requirement here is for
> the zeroing, either via fallocate (which btw posix_fallocate does not
> guarantee) or pwrites of zeros.
Note that even a plain truncate will zero the data visible to the
user. I could see this tring to reduce fragmentation by making sure
the whole file extension is allocated together insted of split up
as the difference processes write their areas. But is there data
showing this fragmentation even happens and actually hurts?
next prev parent reply other threads:[~2023-06-28 9:28 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-22 5:34 Question on slow fallocate Masahiko Sawada
2023-06-22 7:44 ` Wang Yugui
2023-06-22 8:18 ` Masahiko Sawada
2023-06-23 0:47 ` Dave Chinner
2023-06-23 8:29 ` Ritesh Harjani
2023-06-23 10:07 ` Dave Chinner
2023-06-23 11:49 ` Ritesh Harjani
2023-06-23 20:04 ` Eric Sandeen
2023-06-26 3:17 ` Masahiko Sawada
2023-06-26 15:32 ` Eric Sandeen
2023-06-27 15:50 ` Masahiko Sawada
2023-06-27 16:12 ` Eric Sandeen
2023-06-28 4:56 ` Christoph Hellwig [this message]
2023-07-11 22:49 ` Andres Freund
2023-07-19 7:25 ` Dave Chinner
2023-07-19 20:29 ` Andres Freund
2023-07-19 20:38 ` Eric Sandeen
2023-07-19 20:49 ` Eric Sandeen
2023-07-19 22:23 ` Andres Freund
2023-07-11 22:28 ` Andres Freund
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