On Tue, Mar 15, 2016 at 04:12:03PM -0700, James Bottomley wrote: > motion. If you add in one patch and remove in another the code motion > trackers don't see it. Agreed, having the move in a single patch would be nice. > Thirdly, are you sure the pool structure for NVMe should be the same as > for SCSI? We don't do buddy pools for 1,2 or 4 entry transactions in > SCSI just basically because of heuristics, but the packetised io > characteristics of NVMe make single entry lists more likely for it, > don't they? Not really. NVMe doesn't really do packetized I/O. And while people were setting all kinds of nomerge flags early on we're getting rid of them and are seeing similar I/O patterns to fast SCSI devices now. NVMe over PCIe still uses the crazy PRPs by default, which aren't very suitable for this allocator (someone will have to come up with a good mempool for it eventually, though), but we're developing a set of new drivers transporting NVMe command which use SGLs very similar to most SCSI controllers, so using the same SGL allocator is a very natural choice. -- 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
