From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Fri, 11 Feb 2005 21:01:38 +0000 Subject: Re: [ANNOUNCE] hotplug-ng 001 release Message-Id: <20050211210138.GA13940@vrfy.org> List-Id: References: <20050211004033.GA26624@suse.de> In-Reply-To: <20050211004033.GA26624@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Fri, Feb 11, 2005 at 11:46:27PM +0300, Roman Kagan wrote: > On Fri, Feb 11, 2005 at 11:36:27AM -0800, Greg KH wrote: > > Do one thing, and do it well. > > > > udev is for naming devices, not loading modules. > > Well currently udev is doing a lot more: serializing, waiting for sysfs > dir to appear, etc. Not that I disagree with your first statement, > though. Well, we do what we need to do, to make device naming work. All this is mainly a side effect of being able to name device in the order they depend on each other. > > Why, each type of autoload program needs to know how to handle the > > different bus types. So again, a single program doing a single thing > > well. > > udev already pokes enough in sysfs and has quite a lot of > subsystem-specific knowledge, so adding module name generation is not > too much of extra functionality. > > OTOH I'm fine with them being separate programs, provided they get the > necessary info from sysfs so that they can be used for coldplugging too. > This will require adding wait_for_sysfs logic to them, though. In the coldplugging case you don't need to wait for any sysfs file and udevd will wait for you at event driven setups. So there is no need for any software to wait for a file in sysfs. > [ BTW could you please remind the motivation for doing wait_for_sysfs > instead of fixing the kernel to call out the hotplug usermode helper > only after the correspoding sysfs directory has completed initializing? ] We can make the timing a bit better by moving the event generation into the drivers, but this does not solve the problem, as you can't really know what files are created at what time. We still need to do something in userspace. But yes, it would be nice to make the kernel a bit better here, cause the spinning and waiting for attribute costs a lot of CPU what should be avoided. We already working on it, but it will not replace the wait logic completely. Thanks, Kay ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_ide95&alloc_id396&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel