On Fri, Mar 04 2005, Florin Iucha wrote: > Hello, > > For a semester project I am experimenting with a new IO scheduler and I > was trying to set my scheduler to control a single device, to ease the > development and debugging, by using > echo "foo" > /sys/block/ubdc/queue/scheduler > Much to my suprise, this sets the scheduler for the other block > devices as well! Does this happen only to UML block devices? Do I need > to do anything to allow a per-device scheduler? Is the functionality > there, or is it in-progress? Am I reading too much in the fact that > the queue/scheduler is defined under each block device?
It's per-queue. In general that is per-device, apparently that is not so for UML since it shares a queue for several devices. From a cleanliness and performance POV, it's is far better to have a queue per device instead of sharing, I would suggest fixing the uml block device. It looks pretty straight forward to do so, except for ubd_handler(). Which, btw, calls elv_next_request() without holding the queue lock! -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
