On Tuesday 03 June 2008 16:44, Bernard Blackham wrote: > Hi, > > When I switched from udev+udevd to mdev, booting was much faster and it > shaved a decent amount from the total image size. However, I've recently > noticed device nodes sometimes disappearing on boot. The specific > scenario is: > > 1. /dev/ttyS1 exists as a device node in the filesystem on boot - prior > to the actual device existing, and prior to mdev being called. > > 2. echo /bin/mdev > /proc/sys/kernel/hotplug > > 3. a module is loaded that provides ttyS1 > > When this module is loaded, most of the time the existing ttyS1 remains. > Sometimes however, it is unlinked from the filesystem and is never seen > again (until mdev -s is run, or next boot, maybe). > > I pointed my hotplug to a script to log what mdev was being called as, > and found that when the module is loaded, there is actually a remove > event emitted followed by an add event. As there is no locking with > mdev, sometimes mdev runs the remove after the add and thus the device > node goes missing. > > udev seems to have gotten around this using a daemon that serialises > events based on the sequence number provided by the kernel.
How these event seq numbers are passed? Some env variable? -- vda _______________________________________________ busybox mailing list [email protected] http://busybox.net/cgi-bin/mailman/listinfo/busybox
