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From: Jens Axboe <axboe@kernel.dk>
To: Douglas Gilbert <dgilbert@interlog.com>,
	linux-scsi@vger.kernel.org, linux-block@vger.kernel.org
Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com,
	hare@suse.de, kashyap.desai@broadcom.com
Subject: Re: [PATCH] fio: add hipri option to sg engine
Date: Sun, 24 Jan 2021 18:58:50 -0700	[thread overview]
Message-ID: <fef432a4-29ed-c560-1d91-b05bd239b9c9@kernel.dk> (raw)
In-Reply-To: <20210125013751.269675-1-dgilbert@interlog.com>

On 1/24/21 6:37 PM, Douglas Gilbert wrote:
> Adds hipri option to the Linux sg driver engine. This turns on the
> SGV4_FLAG_HIPRI flag in recent sg drivers (January 2021) on READ
> and WRITE commands (and not on UNMAP (trim), VERIFY, etc). Uses
> blk_poll() and the mq_poll() callback in SCSI LLDs. The mechanism
> is also called "iopoll".
> 
> The Linux sg engine in fio uses the struct sg_io_hdr based interface
> known as the sg driver "v3" interface.
> Linux sg drivers in the kernel prior to January 2021 (sg version
> 4.0.12) will just ignore the SGV4_FLAG_HIPRI flag and do normal
> completions where LLDs indicate command completion with a (software)
> interrupt or similar mechanism.

Looks fine, and is consistent with eg io_uring. Can you add the
engine specific option to the HOWTO and fio.1 as well?

-- 
Jens Axboe


      reply	other threads:[~2021-01-25  2:03 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-25  1:37 [PATCH] fio: add hipri option to sg engine Douglas Gilbert
2021-01-25  1:58 ` Jens Axboe [this message]

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