I'm implementing congestion queue management as discussed in the "IO scheduler, queue depth, nr_requests" thread. I've added a list of "parent queues" to the struct request_queue, and if the queue is marked as congested, so are the "parent queues". Now dm needs to be able to say "add this request_queue to the list of parent" for a device. But in dm_table, I cannot get at the request_queue of the dm device. >From a quick look at the code, it seems that tables are never changed "on the fly", but built in advance and then __bind is used to bind a table to a device. If that is the case, then I could iterate over the devices in __bind and call blk_queue_add_parent(dm_dev->bdev->queue, mapped_device->queue) (and blk_queue_remove_parent in __unbind) Is that correct ? And, in general, do you feel this is the correct solution ? Now request_queues know what their parents are, does that complicate things like "dm" too much or is it OK ? Mike. _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
