Hi! > > That's partly why I realy did suggest that we do the async stuff purely in > > the USB layer, rather than try to put it deeper in the device layer. And > > if we do support it "natively" in the device layer like Rafael's latest > > patch, I still think we should be very very nervous about making devices > > async unless there is a measured - and very noticeable - advantage. > > Agreed. Arjan's measurements indicated that USB was one of the biggest > offenders; everything else other than the PS/2 mouse was much faster. > Given these results there isn't much incentive to do anything else > asynchronously. > > (However other devices not present on Arjan's machine may be a > different story. Spinning up multiple external disks is a good example > -- although here it may be necessary for the driver to take charge, > because spinning up a disk requires a lot of power and doing too many > of them at the same time could be bad.) Well, system would better be able to supply enough current... because usb disks auto-sleep on their own, and then something like async ls -l /*/* would kill your machine... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
