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) but has a sync point for ordering. The problem of speeding up boot is different from the one of init processes killing modprobes. There are elements in common, but by and large the biggest headaches at least in large device number boots have already been tackled by the enterprise crowd (they don't like their S390's or 1024 core NUMA systems taking half an hour to come up). James -- 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
