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From: Jens Axboe <axboe@fb.com>
To: Christoph Hellwig <hch@lst.de>,
	Keith Busch <keith.busch@intel.com>,
	"Sagi Grimberg" <sagi@grimberg.me>
Cc: "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Subject: Re: [RFC] optimize nvme single segment I/O
Date: Fri, 22 Mar 2019 15:44:11 +0000	[thread overview]
Message-ID: <302780ee-8721-2039-63b9-0d64bf3b519b@fb.com> (raw)
In-Reply-To: <20190321231037.25104-1-hch@lst.de>

On 3/21/19 5:10 PM, Christoph Hellwig wrote:
> Hi all,
> 
> with all the discussion on small I/O performance lately I thought
> it was time off to dust my old idea to optimize this path a bit
> by avoiding to build a scatterlist.  I've only done very basic
> testing because I've been a bit busy, but I thought it might be
> worthwhile to get it out for feedback.

I ran this through some quick testing, and it's a big win for 4k
IOs here. Around an 8% improvement for cases that are CPU bound.

-- 
Jens Axboe


  parent reply	other threads:[~2019-03-22 15:44 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-21 23:10 [RFC] optimize nvme single segment I/O Christoph Hellwig
2019-03-21 23:10 ` [PATCH 01/15] block: add a req_bvec helper Christoph Hellwig
2019-03-25  5:07   ` Chaitanya Kulkarni
2019-03-27 14:16     ` Christoph Hellwig
2019-03-21 23:10 ` [PATCH 02/15] block: add a rq_integrity_vec helper Christoph Hellwig
2019-03-25  5:10   ` Chaitanya Kulkarni
2019-03-27 14:19     ` Christoph Hellwig
2019-03-21 23:10 ` [PATCH 03/15] block: add a rq_dma_dir helper Christoph Hellwig
2019-03-22 13:06   ` Johannes Thumshirn
2019-03-27 14:20     ` Christoph Hellwig
2019-03-28 10:26       ` Johannes Thumshirn
2019-03-25  5:11   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 04/15] block: add dma_map_bvec helper Christoph Hellwig
2019-03-25  5:13   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 05/15] nvme-pci: remove the unused iod->length field Christoph Hellwig
2019-03-25  5:14   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 06/15] nvme-pci: remove nvme_init_iod Christoph Hellwig
2019-03-25  5:19   ` Chaitanya Kulkarni
2019-03-27 14:21     ` Christoph Hellwig
2019-03-21 23:10 ` [PATCH 07/15] nvme-pci: move the call to nvme_cleanup_cmd out of nvme_unmap_data Christoph Hellwig
2019-03-25  5:21   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 08/15] nvme-pci: merge nvme_free_iod into nvme_unmap_data Christoph Hellwig
2019-03-25  5:22   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 09/15] nvme-pci: only call nvme_unmap_data for requests transferring data Christoph Hellwig
2019-03-25  5:23   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 10/15] nvme-pci: do not build a scatterlist to map metadata Christoph Hellwig
2019-03-25  5:27   ` Chaitanya Kulkarni
2019-08-28  9:20   ` Ming Lei
2019-09-12  1:02     ` Ming Lei
2019-09-12  8:20       ` Christoph Hellwig
2019-03-21 23:10 ` [PATCH 11/15] nvme-pci: split metadata handling from nvme_map_data / nvme_unmap_data Christoph Hellwig
2019-03-25  5:29   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 12/15] nvme-pci: remove the inline scatterlist optimization Christoph Hellwig
2019-03-25  5:30   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 13/15] nvme-pci: optimize mapping of small single segment requests Christoph Hellwig
2019-03-25  5:36   ` Chaitanya Kulkarni
2019-03-21 23:10 ` [PATCH 14/15] nvme-pci: optimize mapping single segment requests using SGLs Christoph Hellwig
2019-03-25  5:39   ` Chaitanya Kulkarni
2019-04-30 14:17   ` Klaus Birkelund
2019-04-30 14:32     ` Christoph Hellwig
2019-03-21 23:10 ` [PATCH 15/15] nvme-pci: tidy up nvme_map_data Christoph Hellwig
2019-03-25  5:40   ` Chaitanya Kulkarni
2019-03-22 15:44 ` Jens Axboe [this message]
2019-03-27 14:24   ` [RFC] optimize nvme single segment I/O Christoph Hellwig
2019-03-22 17:37 ` Keith Busch
2019-03-22 18:55 ` Sagi Grimberg

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