From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 6/6] xfs: avoid COW fork extent lookups in writeback if the fork didn't change
Date: Wed, 11 Jul 2018 19:20:32 +0200 [thread overview]
Message-ID: <20180711172032.GA3738@lst.de> (raw)
In-Reply-To: <20180711171551.GE32415@magnolia>
On Wed, Jul 11, 2018 at 10:15:51AM -0700, Darrick J. Wong wrote:
> Hmm, this troubles me slightly -- a short time ago you removed the "trim
> this data fork mapping to the first overlap with a cow fork mapping"
> (i.e. xfs_reflink_trim_irec_to_next_cow) behavior on the grounds that
> _writepage_map calls _map_blocks for every block in the page and so it
> was unnecessary. But this seems to put that back. Why is that?
Because back then map_blocks did a lookup in the COW fork everytime
(unless we are already on a COW mapping), and this patch wants to
only look it up when the COW fork actually changed, so the trim is
required now.
next prev parent reply other threads:[~2018-07-11 17:24 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-10 6:05 reduce lookups in the COW extent tree Christoph Hellwig
2018-07-10 6:05 ` [PATCH 1/6] xfs: remove if_real_bytes Christoph Hellwig
2018-07-11 16:22 ` Darrick J. Wong
2018-07-10 6:05 ` [PATCH 2/6] xfs: simplify xfs_idata_realloc Christoph Hellwig
2018-07-11 16:23 ` Darrick J. Wong
2018-07-10 6:05 ` [PATCH 3/6] xfs: remove the xfs_ifork_t typedef Christoph Hellwig
2018-07-11 16:23 ` Darrick J. Wong
2018-07-10 6:05 ` [PATCH 4/6] xfs: introduce a new xfs_inode_has_cow_data helper Christoph Hellwig
2018-07-11 16:24 ` Darrick J. Wong
2018-07-10 6:05 ` [PATCH 5/6] xfs: maintain a sequence count for inode fork manipulations Christoph Hellwig
2018-07-10 6:05 ` [PATCH 6/6] xfs: avoid COW fork extent lookups in writeback if the fork didn't change Christoph Hellwig
2018-07-11 17:15 ` Darrick J. Wong
2018-07-11 17:20 ` Christoph Hellwig [this message]
2018-07-11 17:31 ` Darrick J. Wong
2018-07-11 17:35 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2018-07-12 13:49 reduce lookups in the COW extent tree V2 Christoph Hellwig
2018-07-12 13:49 ` [PATCH 6/6] xfs: avoid COW fork extent lookups in writeback if the fork didn't change Christoph Hellwig
2018-07-13 22:51 ` Darrick J. Wong
2018-07-14 0:03 ` Dave Chinner
2018-07-17 13:37 ` Christoph Hellwig
2018-07-17 23:13 ` Dave Chinner
2018-07-17 23:23 reduce lookups in the COW extent tree V3 Christoph Hellwig
2018-07-17 23:24 ` [PATCH 6/6] xfs: avoid COW fork extent lookups in writeback if the fork didn't change Christoph Hellwig
2018-07-18 14:51 ` Carlos Maiolino
2018-07-21 23:23 ` Dave Chinner
2018-07-23 7:49 ` Christoph Hellwig
2018-07-24 22:35 ` Darrick J. Wong
2018-07-27 15:10 ` Christoph Hellwig
2018-08-06 2:37 ` Dave Chinner
2018-08-06 16:45 ` Christoph Hellwig
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