From: Christoph Hellwig <hch@lst.de>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
Keith Busch <keith.busch@intel.com>,
Sagi Grimberg <sagi@grimberg.me>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Hannes Reinecke <hare@suse.de>,
linux-nvme@lists.infradead.org,
Johannes Thumshirn <jthumshirn@suse.de>
Subject: Re: [PATCH 4/7] nvme: implement multipath access to nvme subsystems
Date: Fri, 10 Nov 2017 05:54:18 +0100 [thread overview]
Message-ID: <20171110045418.GB32408@lst.de> (raw)
In-Reply-To: <20171109212217.GA16454@redhat.com>
On Thu, Nov 09, 2017 at 04:22:17PM -0500, Mike Snitzer wrote:
> Your 0th header speaks to the NVMe multipath IO path leveraging NVMe's
> lack of partial completion but I think it'd be useful to have this
> header (that actually gets committed) speak to it.
There is a comment above blk_steal_bios to this respect, which is in
the tree.
> Also, the block core patch to introduce blk_steal_bios() already went in
> but should there be a QUEUE_FLAG that gets set by drivers like NVMe that
> don't support partial completion?
>
> This would make it easier for other future drivers to know whether they
> can use a more optimized IO path.
As-is there is not real need for this. But if you want to use a similar
path in dm-multipath feel free to add the flag when needed.
WARNING: multiple messages have this Message-ID (diff)
From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH 4/7] nvme: implement multipath access to nvme subsystems
Date: Fri, 10 Nov 2017 05:54:18 +0100 [thread overview]
Message-ID: <20171110045418.GB32408@lst.de> (raw)
In-Reply-To: <20171109212217.GA16454@redhat.com>
On Thu, Nov 09, 2017@04:22:17PM -0500, Mike Snitzer wrote:
> Your 0th header speaks to the NVMe multipath IO path leveraging NVMe's
> lack of partial completion but I think it'd be useful to have this
> header (that actually gets committed) speak to it.
There is a comment above blk_steal_bios to this respect, which is in
the tree.
> Also, the block core patch to introduce blk_steal_bios() already went in
> but should there be a QUEUE_FLAG that gets set by drivers like NVMe that
> don't support partial completion?
>
> This would make it easier for other future drivers to know whether they
> can use a more optimized IO path.
As-is there is not real need for this. But if you want to use a similar
path in dm-multipath feel free to add the flag when needed.
next prev parent reply other threads:[~2017-11-10 4:54 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-09 17:44 nvme multipath support V7 Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 17:44 ` [PATCH 1/7] nvme: track subsystems Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 20:23 ` Martin K. Petersen
2017-11-09 20:23 ` Martin K. Petersen
2017-11-09 17:44 ` [PATCH 2/7] nvme: introduce a nvme_ns_ids structure Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 20:25 ` Martin K. Petersen
2017-11-09 20:25 ` Martin K. Petersen
2017-11-09 17:44 ` [PATCH 3/7] nvme: track shared namespaces Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 20:28 ` Martin K. Petersen
2017-11-09 20:28 ` Martin K. Petersen
2017-11-09 17:44 ` [PATCH 4/7] nvme: implement multipath access to nvme subsystems Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 18:17 ` Keith Busch
2017-11-09 18:17 ` Keith Busch
2017-11-09 20:32 ` Martin K. Petersen
2017-11-09 20:32 ` Martin K. Petersen
2017-11-09 21:21 ` Keith Busch
2017-11-09 21:21 ` Keith Busch
2017-11-10 4:52 ` Christoph Hellwig
2017-11-10 4:52 ` Christoph Hellwig
2017-11-10 5:07 ` Christoph Hellwig
2017-11-10 5:07 ` Christoph Hellwig
2017-11-09 21:22 ` Mike Snitzer
2017-11-09 21:22 ` Mike Snitzer
2017-11-10 4:54 ` Christoph Hellwig [this message]
2017-11-10 4:54 ` Christoph Hellwig
2017-11-10 7:27 ` Hannes Reinecke
2017-11-10 7:27 ` Hannes Reinecke
2017-11-09 17:44 ` [PATCH 5/7] nvme: also expose the namespace identification sysfs files for mpath nodes Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 20:33 ` Martin K. Petersen
2017-11-09 20:33 ` Martin K. Petersen
2017-11-10 8:21 ` Hannes Reinecke
2017-11-10 8:21 ` Hannes Reinecke
2017-11-09 17:44 ` [PATCH 6/7] block: create 'slaves' and 'holders' entries for hidden gendisks Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 20:34 ` Martin K. Petersen
2017-11-09 20:34 ` Martin K. Petersen
2017-11-09 17:44 ` [PATCH 7/7] nvme: create 'slaves' and 'holders' entries for hidden controllers Christoph Hellwig
2017-11-09 17:44 ` Christoph Hellwig
2017-11-09 20:34 ` Martin K. Petersen
2017-11-09 20:34 ` Martin K. Petersen
2017-11-10 8:44 ` nvme multipath support V7 Christoph Hellwig
2017-11-10 8:44 ` Christoph Hellwig
2018-04-10 19:32 ` Gruher, Joseph R
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