From: Jeff Garzik <jeff@garzik.org>
To: Matthew Wilcox <matthew@wil.cx>
Cc: Boaz Harrosh <bharrosh@panasas.com>,
Hugh Dickins <hugh@veritas.com>,
Matthew Wilcox <willy@linux.intel.com>,
linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeff Garzik <jgarzik@redhat.com>,
linux-scsi@vger.kernel.org, Jens Axboe <jens.axboe@oracle.com>,
Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
Mark Lord <lkml@rtr.ca>, David Woodhouse <dwmw2@infradead.org>
Subject: Re: New TRIM/UNMAP tree published (2009-05-02)
Date: Sun, 03 May 2009 18:54:06 -0400 [thread overview]
Message-ID: <49FE208E.7070001@garzik.org> (raw)
In-Reply-To: <20090503214836.GV8822@parisc-linux.org>
Matthew Wilcox wrote:
>> (3) when creating a discard request, use block helpers w/ queue-specific
>> knowledge to create either
>> (a) one request, REQ_TYPE_FS, with discard flag or
>> (b) two requests, REQ_TYPE_FS followed by REQ_TYPE_DISCARD
>
> I'm not sure we need option 3b.
Well -- it is a hard requirement to map 1:1 struct request with the
underlying hardware device's command set.
If a device command set lacks a READ-and-DISCARD operation, then you
_must_ create two struct request. Otherwise you break block layer
tagging and other 1:1-based assumptions that exist today.
Thus, given that all of ATA|SCSI|NVMHCI have a DISCARD operation
distinct from other commands...
option 3b is the overwhelming common case.
Jeff
next prev parent reply other threads:[~2009-05-03 22:54 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-02 14:37 [PATCH 1/5] Block: Discard may need to allocate pages Matthew Wilcox
2009-04-02 14:37 ` [PATCH 2/5] Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads Matthew Wilcox
2009-04-02 14:37 ` [PATCH 3/5] ata: Add TRIM infrastructure Matthew Wilcox
2009-04-02 14:37 ` [PATCH 4/5] ide: Add support for TRIM Matthew Wilcox
2009-04-02 14:37 ` [PATCH 5/5] libata: " Matthew Wilcox
2009-04-02 17:20 ` Mark Lord
2009-04-02 17:55 ` Matthew Wilcox
2009-04-16 20:25 ` Mark Lord
2009-04-17 19:44 ` Mark Lord
2009-04-02 15:58 ` [PATCH 4/5] ide: " Sergei Shtylyov
2009-04-02 16:28 ` Matthew Wilcox
2009-04-02 16:38 ` Sergei Shtylyov
2009-04-02 16:51 ` Matthew Wilcox
2009-04-02 19:37 ` Bartlomiej Zolnierkiewicz
2009-04-07 21:38 ` Bartlomiej Zolnierkiewicz
2009-04-07 22:15 ` Matthew Wilcox
2009-04-07 22:26 ` Jeff Garzik
2009-04-07 22:35 ` Bartlomiej Zolnierkiewicz
2009-04-07 17:20 ` Jeff Garzik
2009-04-07 17:57 ` Mark Lord
2009-04-07 18:10 ` Markus Trippelsdorf
2009-04-07 19:58 ` Mark Lord
2009-04-08 7:14 ` Markus Trippelsdorf
2009-04-08 14:25 ` Mark Lord
2009-04-08 14:33 ` Mark Lord
2009-04-08 14:44 ` Dongjun Shin
2009-04-08 14:59 ` Jeff Garzik
2009-04-08 15:50 ` Mark Lord
2009-04-02 15:55 ` [PATCH 3/5] ata: Add TRIM infrastructure Sergei Shtylyov
2009-04-02 16:18 ` Matthew Wilcox
2009-04-02 16:32 ` Sergei Shtylyov
2009-04-02 16:47 ` Matthew Wilcox
2009-04-07 0:02 ` Jeff Garzik
2009-04-05 12:28 ` [PATCH 1/5] Block: Discard may need to allocate pages Boaz Harrosh
2009-04-06 20:34 ` Matthew Wilcox
2009-05-03 6:11 ` Matthew Wilcox
2009-05-03 7:16 ` New TRIM/UNMAP tree published (2009-05-02) Matthew Wilcox
2009-05-03 13:07 ` Hugh Dickins
2009-05-03 14:48 ` Matthew Wilcox
2009-05-03 15:02 ` Boaz Harrosh
2009-05-03 15:42 ` Matthew Wilcox
2009-05-03 16:34 ` Boaz Harrosh
2009-05-03 18:34 ` Jeff Garzik
2009-05-03 18:40 ` Jeff Garzik
2009-05-03 19:04 ` James Bottomley
2009-05-03 19:20 ` Jeff Garzik
2009-05-03 19:37 ` James Bottomley
2009-05-04 14:03 ` Douglas Gilbert
2009-05-04 14:40 ` James Bottomley
2009-05-04 15:11 ` Douglas Gilbert
2009-05-04 15:23 ` James Bottomley
2009-05-03 19:47 ` James Bottomley
2009-05-03 22:47 ` Jeff Garzik
2009-05-04 15:28 ` Boaz Harrosh
2009-05-03 21:48 ` Matthew Wilcox
2009-05-03 22:54 ` Jeff Garzik [this message]
2009-05-03 18:48 ` Bartlomiej Zolnierkiewicz
2009-05-03 15:05 ` Hugh Dickins
2009-04-17 21:23 ` [PATCH 1/5] Block: Discard may need to allocate pages Mark Lord
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