From: Keith Busch <keith.busch@intel.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>
Subject: Re: [PATCH 1/3] nvme/pci: Start request after doorbell ring
Date: Thu, 21 Dec 2017 14:02:50 -0700 [thread overview]
Message-ID: <20171221210250.GA2975@localhost.localdomain> (raw)
In-Reply-To: <118beb1f-54eb-c65d-1c9c-4775ebde1fa8@kernel.dk>
On Thu, Dec 21, 2017 at 01:53:44PM -0700, Jens Axboe wrote:
> Turns out that wasn't what patch 2 was. And the code is right there
> above as well, and under the q_lock, so I guess that race doesn't
> exist.
>
> But that does bring up the fact if we should always be doing the
> nvme_process_cq(nvmeq) after IO submission. For direct/hipri IO,
> maybe it's better to make the submission path faster and skip it?
Yes, I am okay to remove the opprotunistic nvme_process_cq in the
submission path. Even under deeply queued IO, I've not seen this provide
any measurable benefit.
next prev parent reply other threads:[~2017-12-21 21:02 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-21 20:46 [PATCH 0/3] Performance enhancements Keith Busch
2017-12-21 20:46 ` [PATCH 1/3] nvme/pci: Start request after doorbell ring Keith Busch
2017-12-21 20:49 ` Jens Axboe
2017-12-21 20:53 ` Jens Axboe
2017-12-21 21:02 ` Keith Busch [this message]
2017-12-21 21:01 ` Jens Axboe
2018-01-03 20:21 ` Keith Busch
2018-01-23 0:16 ` Keith Busch
2017-12-25 10:12 ` Sagi Grimberg
2017-12-29 9:44 ` Christoph Hellwig
2017-12-25 10:11 ` Sagi Grimberg
2017-12-26 20:35 ` Keith Busch
2017-12-27 9:02 ` Sagi Grimberg
2017-12-29 9:44 ` Christoph Hellwig
2017-12-21 20:46 ` [PATCH 2/3] nvme/pci: Remove cq_vector check in IO path Keith Busch
2017-12-21 20:54 ` Jens Axboe
2017-12-25 10:10 ` Sagi Grimberg
2017-12-27 21:01 ` Sagi Grimberg
2017-12-29 9:48 ` Christoph Hellwig
2017-12-29 15:39 ` Keith Busch
2017-12-31 12:30 ` Sagi Grimberg
2018-01-02 16:50 ` Keith Busch
2017-12-21 20:46 ` [PATCH 3/3] block: Polling completion performance optimization Keith Busch
2017-12-21 20:56 ` Scott Bauer
2017-12-21 21:00 ` Jens Axboe
2017-12-21 21:34 ` Keith Busch
2017-12-21 22:17 ` Jens Axboe
2017-12-21 23:10 ` Keith Busch
2017-12-22 15:40 ` Jens Axboe
2017-12-29 9:50 ` Christoph Hellwig
2017-12-29 15:51 ` Keith Busch
2017-12-31 12:48 ` Sagi Grimberg
2017-12-21 20:57 ` Jens Axboe
2017-12-29 9:51 ` Christoph Hellwig
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