On Mon, 2006-02-06 at 11:54 -0600, Mike Christie wrote: > We actually need ths shost pointer becuase we do not represent the LU in > the kernel. So we go from: > > scsi_host -> host's uspace request_queue (used to pass commands and > messages from the target LLD interrup handler to our netlink > code/userspace -> in userspace we represent the target, device/LU, and host. > > Tomo did you add a virtual scsi_device somewhere? OK, well, the problem is that struct scsi_cmnd is allocated in the critical I/O path. The more elements it has, the more time it takes to set up and tear down. Kenneth Chen of intel has already produced figures showing that you can get measurable I/O improvement simply by dropping fields from it, so I'm very, very reluctant to increase its size. James - : 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
