From: jim owens <jowens@hp.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Ric Wheeler <rwheeler@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
James Bottomley <James.Bottomley@HansenPartnership.com>,
linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Black_David@emc.com,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Tom Coughlan <coughlan@redhat.com>,
Matthew Wilcox <matthew@wil.cx>,
Jens Axboe <jens.axboe@oracle.com>
Subject: Re: thin provisioned LUN support
Date: Tue, 11 Nov 2008 12:07:17 -0500 [thread overview]
Message-ID: <4919BBC5.20809@hp.com> (raw)
In-Reply-To: <20081111164028.GA29902@infradead.org>
Christoph Hellwig wrote:
> Why do most people assume that sending unmap/trim commands for every
> deletet extent ASAP is a good idea?
I agree with you. Thus my earlier assertion:
- trim/unmap for SSD garbage collection has a different goal
than trim/unmap for thin provisioning.
In the SSD garbage collector mode, we want to send them as fast
as we can (per the Intel SSD architect). This allows them to
do their optimizations.
In the Thin Provision mode, we want to delay them as you said:
> So I think not actually doing these on every alloc/free is a good idea.
> Instead the filesystem would free bits when big enough regions happen,
to be filesystem friendly.
But this won't change the block layer. This is a per-filesystem
coding issue to decide when to send the discard.
jim
next prev parent reply other threads:[~2008-11-11 17:07 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-06 14:43 thin provisioned LUN support Ric Wheeler
2008-11-06 15:17 ` James Bottomley
2008-11-06 15:24 ` David Woodhouse
2008-11-06 16:00 ` Ric Wheeler
2008-11-06 16:40 ` Martin K. Petersen
2008-11-06 17:04 ` Ric Wheeler
2008-11-06 17:15 ` Matthew Wilcox
2008-11-07 12:05 ` Jens Axboe
2008-11-07 12:14 ` Ric Wheeler
2008-11-07 12:17 ` David Woodhouse
2008-11-07 12:19 ` Jens Axboe
2008-11-07 14:26 ` thin provisioned LUN support & file system allocation policy Ric Wheeler
2008-11-07 14:34 ` Matthew Wilcox
2008-11-07 14:45 ` Jörn Engel
2008-11-07 14:43 ` Theodore Tso
2008-11-07 14:54 ` Ric Wheeler
2008-11-07 15:26 ` jim owens
2008-11-07 15:31 ` David Woodhouse
2008-11-07 15:35 ` jim owens
2008-11-07 15:46 ` Theodore Tso
2008-11-07 15:51 ` Martin K. Petersen
2008-11-07 16:06 ` Ric Wheeler
2008-11-07 15:56 ` James Bottomley
2008-11-07 15:36 ` James Bottomley
2008-11-07 15:48 ` David Woodhouse
2008-11-07 15:36 ` Theodore Tso
2008-11-07 15:45 ` Matthew Wilcox
2008-11-07 16:07 ` jim owens
2008-11-07 16:12 ` James Bottomley
2008-11-07 16:23 ` jim owens
2008-11-07 16:02 ` Ric Wheeler
2008-11-07 14:55 ` Matthew Wilcox
2008-11-07 15:20 ` thin provisioned LUN support James Bottomley
2008-11-09 23:08 ` Dave Chinner
2008-11-09 23:37 ` James Bottomley
2008-11-10 0:33 ` Dave Chinner
2008-11-10 14:31 ` James Bottomley
2008-11-07 15:49 ` Chris Mason
2008-11-07 16:00 ` Martin K. Petersen
2008-11-07 16:06 ` James Bottomley
2008-11-07 16:11 ` Chris Mason
2008-11-07 16:18 ` James Bottomley
2008-11-07 16:22 ` Ric Wheeler
2008-11-07 16:27 ` James Bottomley
2008-11-07 16:28 ` David Woodhouse
2008-11-07 17:22 ` Chris Mason
2008-11-07 18:09 ` Ric Wheeler
2008-11-07 18:36 ` Theodore Tso
2008-11-07 18:41 ` Ric Wheeler
[not found] ` <49148BDF.9050707@redhat.com>
2008-11-07 19:35 ` Theodore Tso
2008-11-07 19:55 ` Martin K. Petersen
2008-11-07 20:19 ` Theodore Tso
2008-11-07 20:21 ` Matthew Wilcox
[not found] ` <20081107202149.GJ15439@parisc-linux.org>
2008-11-07 20:26 ` Ric Wheeler
2008-11-07 20:48 ` Chris Mason
2008-11-07 21:04 ` Ric Wheeler
2008-11-07 21:13 ` Theodore Tso
2008-11-07 20:42 ` Theodore Tso
2008-11-07 21:06 ` Martin K. Petersen
2008-11-07 20:37 ` Ric Wheeler
2008-11-10 2:44 ` Black_David
2008-11-10 2:36 ` Black_David
2008-11-07 19:44 ` jim owens
2008-11-07 19:48 ` Matthew Wilcox
2008-11-07 19:50 ` Ric Wheeler
2008-11-09 23:36 ` Dave Chinner
2008-11-10 3:40 ` Thin provisioning & arrays Black_David
2008-11-10 8:31 ` Dave Chinner
2008-11-10 9:59 ` David Woodhouse
2008-11-10 13:30 ` Matthew Wilcox
2008-11-10 13:36 ` Jens Axboe
2008-11-10 17:05 ` UNMAP is a hint Black_David
2008-11-10 17:30 ` Matthew Wilcox
2008-11-10 17:56 ` Ric Wheeler
2008-11-10 22:18 ` Thin provisioning & arrays Dave Chinner
2008-11-11 1:23 ` Black_David
2008-11-11 2:09 ` Keith Owens
2008-11-11 13:59 ` Ric Wheeler
2008-11-11 14:55 ` jim owens
2008-11-11 15:38 ` Ric Wheeler
2008-11-11 15:59 ` jim owens
2008-11-11 16:25 ` Ric Wheeler
2008-11-11 16:53 ` jim owens
2008-11-11 23:08 ` Dave Chinner
2008-11-11 23:52 ` jim owens
2008-11-11 22:49 ` Dave Chinner
2008-11-06 15:27 ` thin provisioned LUN support jim owens
2008-11-06 15:57 ` jim owens
2008-11-06 16:21 ` James Bottomley
[not found] ` <yq1d4h8nao5.fsf@sermon.lab.mkp.net>
2008-11-06 15:42 ` Ric Wheeler
2008-11-06 15:57 ` David Woodhouse
2008-11-06 22:36 ` Dave Chinner
2008-11-06 22:55 ` Ric Wheeler
[not found] ` <491375E9.7020707@redhat.com>
2008-11-06 23:06 ` James Bottomley
2008-11-06 23:10 ` Ric Wheeler
2008-11-06 23:26 ` James Bottomley
2008-11-06 23:32 ` thin provisioned LUN support - T10 activity Black_David
2008-11-07 11:59 ` thin provisioned LUN support Artem Bityutskiy
2008-11-10 20:39 ` Aggregating discard requests in the filesystem Matthew Wilcox
2008-11-10 20:44 ` Chris Mason
2008-11-11 0:12 ` Brad Boyer
2008-11-11 15:25 ` jim owens
2008-11-11 16:40 ` thin provisioned LUN support Christoph Hellwig
2008-11-11 17:07 ` jim owens [this message]
2008-11-11 17:33 ` Christoph Hellwig
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