From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Date: Fri, 22 May 2009 14:15:33 +0000
Subject: rules: avoid traversing parent of every single device?
Message-Id: <4A16B385.7000700@tuffmail.co.uk>
List-Id: <linux-hotplug.vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: linux-hotplug@vger.kernel.org

Hi,

I've been looking at what is responsible for all the path lookup 
activity in coldplug.  On my debian stable system, it looks like every 
device gets its parent looked up in sysfs.  I think this is due to 
SUBSYSTEMS matches.

I see the udev default rules are different, but it looks like they still 
test for SUBSYSTEMS on every single device:

SUBSYSTEMS="scsi", ATTRS{type}="1|8", GROUP="tape"
SUBSYSTEMS="scsi", ATTRS{type}="4|5", GROUP="cdrom"
SUBSYSTEMS="scsi", ATTRS{type}="0", GROUP="disk"


Should we add SUBSYSTEM="scsi_generic" to these three rules?

Thanks
Alan