From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Date: Thu, 18 Jan 2001 12:59:54 +0000 Subject: netdevice problem Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org As far as I know, the "vision" is that the hotplug architecture can be used at boot time. We identify all the ISA/PCI/whatever devices and create hotplug insertion events for them, and just let the hotplug magic happen. There are several ways of doing this, most notably: a) Buffer the results of the bootup PCI scan and spit out hotplug events after filesystems have been mounted, etc. b) Scan the buses from initscripts, synthesise hotplug events from userspace. Both approaches are broken, because we'll end up running /sbin/hotplug N times concurrently. The assignment of eth0, eth1, eth2, etc will be totally random and people will hate us. The fixes appear to be: 1: Funky hard-wired delay in the hotplug synthesiser. (cs89x0 will require five seconds, please...) 2: Funky userland locking which blocks each hotplug synthesis until the previous one has completed its `ifconfig up', if it indeed did it. This is crap. 3: Stick with modutils.conf to drive the bootup process, switch to hotplug scripts for post-boot insert/remove. This is a sad mix. 4: Rework call_usermodehelper for synchronous (or completion callback) semantics. So the pci layer's callout doesn't return until both 'hotplug pci' and its child, 'hotplug net' have terminated. Option 4 is of course the patch-which-didn't-make-it. I haven't resubmitted because the jury is still out on whether it's still needed. If the current setup can be reasonably used from userspace then let's not hassle Linus. But I now feel it's needed. Any clever ideas out there? _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel