On Sun, 2007-06-03 at 08:28 +0300, Avi Kivity wrote: > Sure, 'used' is important (how else do you get the packet size on > receive?) Well, the sender can prepend the length, or for networking just leave Linux to trim packets. It's the trust issue which bugs me. > , I'm just bitching about the linear scan. If you're doing interrupt mitigation on a high-bandwidth device, I think it's optimal. And if you're not, you obviously don't care 8) That said, thousands of descriptors may not be insane... > Well, if you have 256 slots per direction, you will scan 4KB of memory > per interrupt (256 slots x 2 directions x 8 bytes). You may need a > queue length greater than 256 for a high bandwidth interface, if you > want to reduce your interrupt rate, or if your guest is scheduled out > for lengthy periods (say, a millisecond). Hmm... Perhaps I should move the used arrays into the "struct virtio_device" and guarantee that the id (returned by add_*buf) is an index into that. Then we can trivially add a corresponding bit array. This also makes the "id" easier to use from the driver side: if we add a "max_id" field it can size its own arrays if it wants to. Gets rid of the linked-list in the block driver... Thoughts? Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
