From: Christoph Hellwig <hch@infradead.org>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Bart Van Assche <bvanassche@acm.org>,
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 23:48:47 -0700 [thread overview]
Message-ID: <20130821064847.GA9043@infradead.org> (raw)
In-Reply-To: <1377031084.5302.54.camel@haakon3.risingtidesystems.com>
On Tue, Aug 20, 2013 at 01:38:04PM -0700, Nicholas A. Bellinger wrote:
> <yawn>, I only care about the performance against upstream code, so that
> would mean scsi_debug here. Typically the onus of demonstrating a
> performance improvement is on the patch submitter (eg: not the
> reviewer).
Do you really care? If the patchset introduced a lot of code or
ugliness I might agreee to your above statement, but it actually
makes the code more obvious, simpler and also fixes some small issues
so I don't think we'll need an exact performance improvement to justify
it.
> But it would be at least useful to know the actual benefit with results
> as an incremental step, short of avoiding this code entirely for
> scsi-mq.
I don't think you can avoid the device put/get entirely for that case.
I've been looking over the mq code a bit more lately, and in a few
places it just seems to try to cut a few too many corners. To get
it out of the prototype status we'll need to make sure all edge cases
are handled correctly.
next prev parent reply other threads:[~2013-08-21 6:48 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
2013-08-20 20:38 ` Nicholas A. Bellinger
2013-08-21 6:48 ` Christoph Hellwig [this message]
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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