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From: Matthew Wilcox <willy@infradead.org>
To: hch@infradead.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-xfs@vger.kernel.org
Subject: [RFC 0/2] Begin switching iomap from apply to iter
Date: Wed,  1 Apr 2020 08:25:20 -0700	[thread overview]
Message-ID: <20200401152522.20737-1-willy@infradead.org> (raw)

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

I don't like the 'apply' design pattern.  It splits the logic between
two functions, and from a performance point of view, it introduces an
indirect function call which is more expensive due to Spectre.  This rfc
only converts one function over to use the new API as a demonstration.
I don't want to waste time on it if people aren't interested in this
approach.

I haven't tested this at all; it's probably buggy.

Matthew Wilcox (Oracle) (2):
  iomap: Add iomap_iter API
  iomap: Convert page_mkwrite to iter API

 fs/iomap/Makefile      |  2 +-
 fs/iomap/buffered-io.c | 51 ++++++++++----------------
 fs/iomap/iter.c        | 81 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/iomap.h  | 24 +++++++++++++
 4 files changed, 125 insertions(+), 33 deletions(-)
 create mode 100644 fs/iomap/iter.c

-- 
2.25.1


             reply	other threads:[~2020-04-01 15:25 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-01 15:25 Matthew Wilcox [this message]
2020-04-01 15:25 ` [PATCH 1/2] iomap: Add iomap_iter API Matthew Wilcox
2020-04-01 15:42   ` Christoph Hellwig
2020-04-01 18:42     ` Matthew Wilcox
2020-04-22 15:19       ` Jan Kara
2020-04-01 19:20     ` Matthew Wilcox
2020-04-02  7:48       ` Christoph Hellwig
2020-04-01 15:25 ` [PATCH 2/2] iomap: Convert page_mkwrite to iter API Matthew Wilcox

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