From: Christoph Hellwig <hch@infradead.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
axboe@kernel.dk, hch@infradead.org, akpm@linux-foundation.org,
torvalds@linux-foundation.org, martin.petersen@oracle.com,
linux-api@vger.kernel.org, linux-kernel@vger.kernel.org,
shane.seymour@hpe.com, bfields@fieldses.org,
linux-fsdevel@vger.kernel.org, jlayton@poochiereds.net
Subject: Re: [PATCH v5.1 0/2] create BLKZEROOUT ioctl that invalidates page cache
Date: Wed, 2 Mar 2016 01:44:16 -0800 [thread overview]
Message-ID: <20160302094416.GA16631@infradead.org> (raw)
In-Reply-To: <1889689.0axyUkdxkf@wuerfel>
On Wed, Mar 02, 2016 at 10:15:02AM +0100, Arnd Bergmann wrote:
> I'm missing the background on this, just saw the patch fly by,
> so sorry if this has been asked before:
>
> Why do you want to invalidate the cache? Is this to save RAM
> or is something else going to write here and you have to invalidate
> it for correctness?
BLKZEROOUT can be though as a direct I/O operation - it issues a
WRITE SAME (or similar) command straight to the device to zero
the specified range. If there was cached data for this range it would
now be stale.
next prev parent reply other threads:[~2016-03-02 9:44 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-02 4:09 [PATCH v5.1 0/2] create BLKZEROOUT ioctl that invalidates page cache Darrick J. Wong
2016-03-02 4:09 ` [PATCH 1/2] block: invalidate the page cache when issuing BLKZEROOUT Darrick J. Wong
2016-03-02 9:19 ` Christoph Hellwig
2016-03-02 4:09 ` [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Darrick J. Wong
2016-03-02 9:20 ` Christoph Hellwig
2016-03-02 18:52 ` Linus Torvalds
2016-03-02 22:56 ` Darrick J. Wong
2016-03-02 23:49 ` Linus Torvalds
2016-03-03 17:02 ` Theodore Ts'o
2016-03-03 17:55 ` Linus Torvalds
2016-03-03 18:00 ` Christoph Hellwig
2016-03-03 18:14 ` Martin K. Petersen
2016-03-03 18:21 ` Theodore Ts'o
2016-03-03 18:01 ` Martin K. Petersen
2016-03-03 18:09 ` Christoph Hellwig
2016-03-03 18:12 ` Darrick J. Wong
2016-03-03 18:54 ` Martin K. Petersen
2016-03-03 22:39 ` Theodore Ts'o
2016-03-03 23:10 ` Dave Chinner
2016-03-04 0:20 ` Theodore Ts'o
2016-03-09 22:20 ` Gregory Farnum
2016-03-09 23:08 ` Theodore Ts'o
2016-03-10 14:58 ` Ric Wheeler
2016-03-10 18:33 ` Linus Torvalds
2016-03-10 21:47 ` Theodore Ts'o
2016-03-11 4:42 ` Ric Wheeler
2016-03-11 13:59 ` One Thousand Gnomes
2016-03-11 15:27 ` Theodore Ts'o
2016-03-11 17:23 ` Linus Torvalds
2016-03-11 17:30 ` Andy Lutomirski
2016-03-11 18:25 ` Linus Torvalds
2016-03-11 22:30 ` Dave Chinner
2016-03-12 0:33 ` Linus Torvalds
2016-03-12 0:35 ` Theodore Ts'o
2016-03-12 0:44 ` Linus Torvalds
2016-03-12 7:19 ` Theodore Ts'o
2016-03-12 10:11 ` Thomas Schoebel-Theuer
2016-03-13 23:30 ` Dave Chinner
2016-03-14 10:34 ` Ric Wheeler
2016-03-14 14:46 ` Theodore Ts'o
2016-03-15 20:14 ` Dave Chinner
2016-03-15 20:43 ` Linus Torvalds
2016-03-15 21:29 ` Theodore Ts'o
2016-03-15 22:33 ` Dave Chinner
2016-03-15 22:52 ` Theodore Ts'o
2016-03-16 1:51 ` Darrick J. Wong
2016-03-16 21:45 ` Andreas Dilger
2016-03-17 0:15 ` Theodore Ts'o
2016-03-17 0:33 ` Eric Sandeen
2016-03-17 0:59 ` Theodore Ts'o
2016-03-17 5:18 ` Gregory Farnum
2016-03-17 12:36 ` Theodore Ts'o
2016-03-17 17:47 ` Linus Torvalds
2016-03-17 17:50 ` Ric Wheeler
2016-03-17 17:59 ` Linus Torvalds
2016-03-17 18:35 ` Chris Mason
2016-03-17 20:49 ` Andreas Dilger
2016-03-17 21:00 ` Chris Mason
2016-03-18 3:20 ` Theodore Ts'o
2016-03-18 15:15 ` Jeff Moyer
2016-03-18 20:05 ` Martin K. Petersen
2016-03-18 6:52 ` Gregory Farnum
2016-03-18 7:19 ` Linus Torvalds
2016-03-17 1:01 ` Dave Chinner
2016-03-17 2:38 ` Darrick J. Wong
2016-03-18 22:55 ` NeilBrown
2016-03-15 23:06 ` Linus Torvalds
2016-03-15 23:14 ` Linus Torvalds
2016-03-16 0:08 ` Dave Chinner
2016-03-15 23:52 ` Dave Chinner
2016-03-16 0:06 ` Linus Torvalds
2016-03-16 0:30 ` Eric Sandeen
2016-03-16 0:51 ` Chris Mason
2016-03-16 22:23 ` Chris Mason
2016-03-17 13:49 ` Ric Wheeler
2016-03-15 22:38 ` Eric Sandeen
2016-03-03 22:56 ` Dave Chinner
2016-03-04 2:30 ` Thomas Schoebel-Theuer
2016-03-03 18:14 ` Linus Torvalds
2016-03-02 9:15 ` [PATCH v5.1 0/2] create BLKZEROOUT ioctl that invalidates page cache Arnd Bergmann
2016-03-02 9:44 ` Christoph Hellwig [this message]
2016-03-02 10:55 ` Arnd Bergmann
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