On Thu 2014-09-11 13:23:54, Dmitry Torokhov wrote: > On Thu, Sep 11, 2014 at 12:59:25PM -0700, James Bottomley wrote: > > > > On Tue, 2014-09-09 at 16:01 -0700, Dmitry Torokhov wrote: > > > On Tuesday, September 09, 2014 03:46:23 PM James Bottomley wrote: > > > > On Wed, 2014-09-10 at 07:41 +0900, Tejun Heo wrote: > > > > > > > > > > The thing is that we have to have dynamic mechanism to listen for > > > > > device attachments no matter what and such mechanism has been in place > > > > > for a long time at this point. The synchronous wait simply doesn't > > > > > serve any purpose anymore and kinda gets in the way in that it makes > > > > > it a possibly extremely slow process to tell whether loading of a > > > > > module succeeded or not because the wait for the initial round of > > > > > probe is piggybacked. > > > > > > > > OK, so we just fire and forget in userland ... why bother inventing an > > > > elaborate new infrastructure in the kernel to do exactly what > > > > > > > > modprobe <mod> & > > > > > > > > would do? > > > > > > Just so we do not forget: we also want the no-modules case to also be able > > > to probe asynchronously so that a slow device does not stall kernel booting. > > > > Yes, but we mostly do this anyway. SCSI for instance does asynchronous > > scanning of attached devices (once the cards are probed) > > What would it do it card was a bit slow to probe? > > > but has a sync > > point for ordering. > > Quite often we do not really care about ordering of devices. I mean, > does it matter if your mouse is discovered before your keyboard or > after? Actually yes, I suspect it does. I do evtest /dev/input/eventX by hand, occassionaly. It would be annoying if they moved between reboots. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
