From: Bart Van Assche <bvanassche@acm.org>
To: scameron@beardog.cce.hp.com
Cc: linux-scsi@vger.kernel.org, stephenmcameron@gmail.com, dab@hp.com
Subject: Re: SCSI mid layer and high IOPS capable devices
Date: Tue, 11 Dec 2012 09:21:46 +0100 [thread overview]
Message-ID: <50C6ED1A.7040404@acm.org> (raw)
In-Reply-To: <20121211000013.GI23107@beardog.cce.hp.com>
On 12/11/12 01:00, scameron@beardog.cce.hp.com wrote:
> I tried using scsi_debug with fake_rw and also the scsi_ram driver
> that was recently posted to get some idea of what the maximum IOPS
> that could be pushed through the SCSI midlayer might be, and the
> numbers were a little disappointing (was getting around 150k iops
> with scsi_debug with reads and writes faked, and around 3x that
> with the block driver actually doing the i/o).
With which request size was that ? I see about 330K IOPS @ 4 KB and
about 540K IOPS @ 512 bytes with the SRP protocol, a RAM disk at the
target side, a single SCSI LUN and a single IB cable. These results have
been obtained on a setup with low-end CPU's. Had you set rq_affinity to
2 in your tests ?
Bart.
next prev parent reply other threads:[~2012-12-11 8:21 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-11 0:00 SCSI mid layer and high IOPS capable devices scameron
2012-12-11 8:21 ` Bart Van Assche [this message]
2012-12-11 22:46 ` scameron
2012-12-13 11:40 ` Bart Van Assche
2012-12-13 18:03 ` scameron
2012-12-13 17:18 ` Bart Van Assche
2012-12-13 15:22 ` Bart Van Assche
2012-12-13 17:25 ` scameron
2012-12-13 16:47 ` Bart Van Assche
2012-12-13 16:49 ` Christoph Hellwig
2012-12-14 9:44 ` Bart Van Assche
2012-12-14 16:44 ` scameron
2012-12-14 16:15 ` Bart Van Assche
2012-12-14 19:55 ` scameron
2012-12-14 19:28 ` Bart Van Assche
2012-12-14 21:06 ` scameron
2012-12-15 9:40 ` Bart Van Assche
2012-12-19 14:23 ` Christoph Hellwig
2012-12-13 21:20 ` scameron
2012-12-14 0:22 ` Jack Wang
[not found] ` <CADzpL0TMT31yka98Zv0=53N4=pDZOc9+gacnvDWMbj+iZg4H5w@mail.gmail.com>
[not found] ` <006301cdd99c$35099b40$9f1cd1c0$@com>
[not found] ` <CADzpL0S5cfCRQftrxHij8KOjKj55psSJedmXLBQz1uQm_SC30A@mail.gmail.com>
2012-12-14 4:59 ` Jack Wang
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