Re: [RFC PATCH] SCSI host lock push-down

From: Jeff Garzik
Date: Sun Nov 07 2010 - 11:54:35 EST


On 11/06/2010 05:31 AM, Stefan Richter wrote:
Jeff Garzik wrote:
An alternate arrangement, not presented by this patch, might
be preferred: in order to make it clear that queuecommand
locking has changed, one could s/queuecommand/queuecommand_nl/ in
Scsi_Host_Template, in order to guarantee that drivers are either
(a) upgraded or (b) broken at compile time. Compile-time detection of
new locking may be desirable, and I'll volunteer to change my patch to
do that, if community members prefer that route instead of below.

I followed only a fraction of the related discussion. Thus I wonder why a
renaming of scsi_host_template.queuecommand was not part of these attempts
from the very outset.

Given the choice between compile-time breakage of unconverted drivers and
silent invalidation of potential locking assumptions at runtime, the
preferable way forward is quite clear IMO.

I am leaning towards a rename, but wanted to see what others thought.


(Since no coexistence period of .queuecommand and .queuecommand_nl or
.unlocked_queuecommand is planned, how about you rename it to .queue_command?
Follows Linux naming conventions more closely.)

To me, that name lacks a clear "locking changed" signal, for a random engineer who simply stumbles upon the queuecommand -> queue_command rename change one day.

Jeff


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/