From: Bart Van Assche <bvanassche@acm.org>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: James Bottomley <jbottomley@parallels.com>,
Mike Christie <michaelc@cs.wisc.edu>,
Hannes Reinecke <hare@suse.de>,
David Milburn <dmilburn@redhat.com>,
linux-scsi <linux-scsi@vger.kernel.org>
Subject: Re: SCSI core patches for kernel 3.12
Date: Tue, 20 Aug 2013 20:00:29 +0200 [thread overview]
Message-ID: <5213AEBD.2020303@acm.org> (raw)
In-Reply-To: <1377018283.5302.48.camel@haakon3.risingtidesystems.com>
On 08/20/13 19:04, Nicholas A. Bellinger wrote:
> On Tue, 2013-08-20 at 18:15 +0200, Bart Van Assche wrote:
>> On 08/20/13 18:11, Nicholas A. Bellinger wrote:
>>> On Tue, 2013-08-20 at 14:05 +0200, Bart Van Assche wrote:
>>>> This patch series consists of four patches that address device removal
>>>> issues and three patches that improve performance of the SCSI mid-layer.
>>>
>>> Perhaps it would be useful to know what the performance improvement
>>> actually is..? Eg: fio numbers before and after.
>>
>> The optimizations in this patch series are micro-optimizations. Their
>> performance impact is small but measurable. Peak IOPS results are
>> improved by about 1% by each of these performance improvements for a
>> low-latency transport.
>
> So that is 250K to 252.5K per LUN, or what..?
The exact numbers depend on the number of CPU's in the initiator system,
the number of CPU's in the target system, the transport type, HCA model,
SCSI target stack configuration, target storage medium etc. If you want
to verify yourself the impact of this patch without all these
dependencies, that's possible by running a test against the scsi_debug
driver.
Bart.
next prev parent reply other threads:[~2013-08-20 18:00 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-20 12:05 SCSI core patches for kernel 3.12 Bart Van Assche
2013-08-20 12:06 ` [PATCH 1/7] Introduce scsi_device_being_removed() Bart Van Assche
2013-09-01 16:43 ` Christoph Hellwig
2013-08-20 12:07 ` [PATCH 2/7] Rework scsi_internal_device_unblock() Bart Van Assche
2013-09-01 16:44 ` Christoph Hellwig
2013-08-20 12:08 ` [PATCH 3/7] Avoid re-enabling I/O after the transport became offline Bart Van Assche
2013-09-01 16:46 ` Christoph Hellwig
2013-08-20 12:08 ` [PATCH 4/7] Disallow changing the device state via sysfs into "deleted" Bart Van Assche
2013-09-01 16:49 ` Christoph Hellwig
2013-09-02 18:59 ` Bart Van Assche
2013-09-02 19:06 ` Christoph Hellwig
2013-09-02 19:12 ` Bart Van Assche
2013-09-02 19:17 ` Christoph Hellwig
2013-08-20 12:09 ` [PATCH 5/7] Micro-optimize scsi_request_fn() Bart Van Assche
2013-09-01 16:50 ` Christoph Hellwig
2013-08-20 12:09 ` [PATCH 6/7] Rename scsi_get_command() and scsi_put_command() Bart Van Assche
2013-08-20 12:10 ` [PATCH 7/7] Micro-optimize scsi_next_command() Bart Van Assche
2013-09-01 17:06 ` Christoph Hellwig
2013-09-01 17:08 ` [PATCH 8/7] scsi: cleanup scsi_requeue_command Christoph Hellwig
2013-08-20 16:11 ` SCSI core patches for kernel 3.12 Nicholas A. Bellinger
2013-08-20 16:15 ` Bart Van Assche
2013-08-20 17:04 ` Nicholas A. Bellinger
2013-08-20 18:00 ` Bart Van Assche [this message]
2013-08-20 20:38 ` Nicholas A. Bellinger
2013-08-21 6:48 ` Christoph Hellwig
2013-08-21 7:35 ` Nicholas A. Bellinger
2013-10-02 7:40 ` Christoph Hellwig
2013-10-02 15:15 ` James Bottomley
2013-10-02 16:17 ` Christoph Hellwig
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