From: John Garry <john.g.garry@oracle.com>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 0/5] xfs: allocation alignment for forced alignment
Date: Mon, 29 Apr 2024 15:06:16 +0100 [thread overview]
Message-ID: <083f3d88-cd39-41ef-9ee1-cafe04a96cf9@oracle.com> (raw)
In-Reply-To: <20240402233006.1210262-1-david@fromorbit.com>
On 03/04/2024 00:28, Dave Chinner wrote:
> Extent alignment is currently driven by multiple variables that come
> from different sources and are applied at different times. Stripe
> alignment currently defines the extent start alignment, whilst
> extent size hints only affect the extent length and not the start
> alignment.
BTW, I have been testing stripe alignment for this series vs mainline
(v6.9-rc1), and I find that I more often get stripe-aligned extents with
this series. I guess that you expected that.
However, we do seem to make more trips into the block allocator for
that. For example, writing a new file with 6014 blocks and sunit=16:
this series bmap:
File size of /root/mnt2/file_48 is 24630784 (6014 blocks of 4096 bytes)
/root/mnt2/file_48:
EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL FLAGS
0: [0..48111]: 547456..595567 1 (240768..288879) 48112 000111
The block allocator gave 1x 6014 block
mainline:
/root/mnt2/file_48:
EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL FLAGS
0: [0..48111]: 547440..595551 1 (240752..288863) 48112 001111
The block allocator gave 1x 6000 and 1x 14 blocks, which are contiguous.
Let me know if you want more details on this. Obviously more often
aligned extents is nice, but more trips to the block allocator isn't.
Thanks,
John
prev parent reply other threads:[~2024-04-29 14:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-02 23:28 [PATCH 0/5] xfs: allocation alignment for forced alignment Dave Chinner
2024-04-02 23:28 ` [PATCH 1/5] xfs: only allow minlen allocations when near ENOSPC Dave Chinner
2024-04-03 16:31 ` John Garry
2024-04-03 23:15 ` Dave Chinner
2024-04-04 13:54 ` John Garry
2024-04-02 23:28 ` [PATCH 2/5] xfs: always tail align maxlen allocations Dave Chinner
2024-04-02 23:28 ` [PATCH 3/5] xfs: simplify extent allocation alignment Dave Chinner
2024-04-02 23:28 ` [PATCH 4/5] xfs: make EOF allocation simpler Dave Chinner
2024-04-02 23:28 ` [PATCH 5/5] xfs: introduce forced allocation alignment Dave Chinner
2024-04-10 12:44 ` [PATCH 0/5] xfs: allocation alignment for forced alignment John Garry
2024-04-16 0:38 ` Dave Chinner
2024-04-16 6:51 ` John Garry
2024-04-29 14:06 ` John Garry [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=083f3d88-cd39-41ef-9ee1-cafe04a96cf9@oracle.com \
--to=john.g.garry@oracle.com \
--cc=david@fromorbit.com \
--cc=linux-xfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).