Sorry, I find that the patch of "virtio-scsi: Optimize virtio_scsi_init_req" can slove this problem.
By the way, can you tell me the reason of the change about cdb and sense? On 2015-2-3 10:31, Wangting (Kathy) wrote: > Hi Paolo, > > Recently I test IO performance with virtio-scsi, and find out that the patch > of > "virtio-scsi: add support for the any_layout feature" affects IO performance > of model > with 4KB 32iodepth sequence read. > > Why cdb and sense is removed from the struct of VirtIOSCSICmdReq and > VirtIOSCSICmdResp? > How do you consider the impact of the changes to the performance? > Although the latest version of qemu can optimize the performance by the way > of reading merger, > I think the affect of this patch cannot be ignored. > > Best wishes, > > Ting >
