From: Christoph Hellwig <hch@infradead.org>
To: Ric Wheeler <rwheeler@redhat.com>
Cc: Greg Freemyer <greg.freemyer@gmail.com>, Mark Lord <liml@rtr.ca>,
Matthew Wilcox <matthew@wil.cx>,
Christoph Hellwig <hch@infradead.org>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
jens.axboe@oracle.com, james.bottomley@hansenpartnership.com,
willy@wil.cx, jgarzik@pobox.com, sandeen@redhat.com,
linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: [PATCH 1/4] block: Allow devices to indicate whether discarded blocks are zeroed
Date: Mon, 23 Nov 2009 12:03:25 -0500 [thread overview]
Message-ID: <20091123170325.GA23217@infradead.org> (raw)
In-Reply-To: <4B0AC038.6050606@redhat.com>
On Mon, Nov 23, 2009 at 12:02:48PM -0500, Ric Wheeler wrote:
> I agree - the discard of the whole device is a good idea.
>
> I just want to make clear that "discard block X; write block X with
> zeroed data" undoes the discard in general :-)
We can skip the writing of zeroes if we know the device returns zeroed
blocks after a trim. Martin's patch exports that information to
userspace, and once we have a nice enough interface (e.g. blkid or an
ioctl) we can actually use it in mkfs to optimize the writing of zeroes
away. Raw growling in sysfs is a bit too nasty to add it to mkfs for
those few blocks IMHO.
next prev parent reply other threads:[~2009-11-23 17:03 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-21 2:45 Thin provisioning fixes Martin K. Petersen
2009-11-21 2:45 ` [PATCH 1/4] block: Allow devices to indicate whether discarded blocks are zeroed Martin K. Petersen
2009-11-21 10:13 ` Christoph Hellwig
2009-11-21 19:58 ` Matthew Wilcox
2009-11-22 2:43 ` Mark Lord
2009-11-23 16:37 ` Ric Wheeler
2009-11-23 16:54 ` Greg Freemyer
2009-11-23 17:02 ` Ric Wheeler
2009-11-23 17:03 ` Christoph Hellwig [this message]
2009-11-23 17:50 ` Eric Sandeen
2009-11-23 17:05 ` Christoph Hellwig
2009-11-21 12:50 ` Ric Wheeler
2009-11-21 20:17 ` Martin K. Petersen
2009-11-21 2:45 ` [PATCH 2/4] sd: WRITE SAME(16) / UNMAP support Martin K. Petersen
2009-11-21 2:45 ` [PATCH 3/4] libata: Report zeroed read after Trim and max discard size Martin K. Petersen
2009-11-21 10:49 ` Christoph Hellwig
2009-11-21 20:16 ` Martin K. Petersen
2009-11-24 14:35 ` Christoph Hellwig
2009-11-24 15:20 ` Mark Lord
2009-11-24 15:21 ` Christoph Hellwig
2009-11-21 2:45 ` [PATCH 4/4] libata: Fix garbled Trim payload Martin K. Petersen
2009-11-21 10:47 ` Christoph Hellwig
2009-11-21 19:50 ` Martin K. Petersen
2009-11-21 4:56 ` Thin provisioning fixes Eric Sandeen
2009-11-21 6:08 ` Martin K. Petersen
2009-11-21 6:55 ` Martin K. Petersen
2009-11-26 10:59 ` Christoph Hellwig
2009-11-26 11:01 ` Jens Axboe
2009-11-26 11:05 ` Christoph Hellwig
2009-11-26 15:13 ` Mark Lord
2009-11-26 15:14 ` Mark Lord
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