On Mon, Apr 23, 2018 at 10:59:43PM +0300, Michael S. Tsirkin wrote: > On Mon, Apr 23, 2018 at 03:31:20PM -0400, Konrad Rzeszutek Wilk wrote: > > On Mon, Apr 23, 2018 at 01:34:52PM +0800, Jason Wang wrote: > > > Hi all: > > > > > > This RFC implement packed ring layout. The code were tested with > > > Tiwei's RFC V2 a thttps://lkml.org/lkml/2018/4/1/48. Some fixups and > > > tweaks were needed on top of Tiwei's code to make it run. TCP stream > > > and pktgen does not show obvious difference compared with split ring. > > > > I have to ask then - what is the benefit of this? > > You can use this with dpdk within guest. > The DPDK version did see a performance improvement so hopefully with Is there a link to this performance improvement document? > future versions this will too. > > > > > > > Changes from V2: > > > - do not use & in checking desc_event_flags > > > - off should be most significant bit > > > - remove the workaround of mergeable buffer for dpdk prototype > > > - id should be in the last descriptor in the chain > > > - keep _F_WRITE for write descriptor when adding used > > > - device flags updating should use ADDR_USED type > > > - return error on unexpected unavail descriptor in a chain > > > - return false in vhost_ve_avail_empty is descriptor is available > > > - track last seen avail_wrap_counter > > > - correctly examine available descriptor in get_indirect_packed() > > > - vhost_idx_diff should return u16 instead of bool > > > > > > Changes from V1: > > > > > > - Refactor vhost used elem code to avoid open coding on used elem > > > - Event suppression support (compile test only). > > > - Indirect descriptor support (compile test only). > > > - Zerocopy support. > > > - vIOMMU support. > > > - SCSI/VSOCK support (compile test only). > > > - Fix several bugs > > > > > > For simplicity, I don't implement batching or other optimizations. > > > > > > Please review. > > > > > > Jason Wang (8): > > > vhost: move get_rx_bufs to vhost.c > > > vhost: hide used ring layout from device > > > vhost: do not use vring_used_elem > > > vhost_net: do not explicitly manipulate vhost_used_elem > > > vhost: vhost_put_user() can accept metadata type > > > virtio: introduce packed ring defines > > > vhost: packed ring support > > > vhost: event suppression for packed ring > > > > > > drivers/vhost/net.c | 136 ++---- > > > drivers/vhost/scsi.c | 62 +-- > > > drivers/vhost/vhost.c | 824 ++++++++++++++++++++++++++++++++++--- > > > drivers/vhost/vhost.h | 47 ++- > > > drivers/vhost/vsock.c | 42 +- > > > include/uapi/linux/virtio_config.h | 9 + > > > include/uapi/linux/virtio_ring.h | 32 ++ > > > 7 files changed, 926 insertions(+), 226 deletions(-) > > > > > > -- > > > 2.7.4 > > >
