Re: [PATCH net-next V5 0/9] vhost_net rx batch dequeuing

[Jason Wang]

On 2017å05æ18æ 04:59, Michael S. Tsirkin wrote:
> On Wed, May 17, 2017 at 12:14:36PM +0800, Jason Wang wrote:
> > This series tries to implement rx batching for vhost-net. This is done
> > by batching the dequeuing from skb_array which was exported by
> > underlayer socket and pass the sbk back through msg_control to finish
> > userspace copying. This is also the requirement for more batching
> > implemention on rx path.
> >
> > Tests shows at most 7.56% improvment bon rx pps on top of batch
> > zeroing and no obvious changes for TCP_STREAM/TCP_RR result.
> >
> > Please review.
> >
> > Thanks
> A surprisingly large gain for such as simple change.  It would be nice
> to understand better why this helps - in particular, does the optimal
> batch size change if ring is bigger or smaller?

Will test, just want to confirm. You mean virtio ring not tx_queue_len here?

Thanks

> But let's merge it
> meanwhile.
>
> Series:
>
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
>
>
> > Changes from V4:
> > - drop batch zeroing patch
> > - renew the performance numbers
> > - move skb pointer array out of vhost_net structure
> >
> > Changes from V3:
> > - add batch zeroing patch to fix the build warnings
> >
> > Changes from V2:
> > - rebase to net-next HEAD
> > - use unconsume helpers to put skb back on releasing
> > - introduce and use vhost_net internal buffer helpers
> > - renew performance numbers on top of batch zeroing
> >
> > Changes from V1:
> > - switch to use for() in __ptr_ring_consume_batched()
> > - rename peek_head_len_batched() to fetch_skbs()
> > - use skb_array_consume_batched() instead of
> >    skb_array_consume_batched_bh() since no consumer run in bh
> > - drop the lockless peeking patch since skb_array could be resized, so
> >    it's not safe to call lockless one
> >
> > Jason Wang (8):
> >    skb_array: introduce skb_array_unconsume
> >    ptr_ring: introduce batch dequeuing
> >    skb_array: introduce batch dequeuing
> >    tun: export skb_array
> >    tap: export skb_array
> >    tun: support receiving skb through msg_control
> >    tap: support receiving skb from msg_control
> >    vhost_net: try batch dequing from skb array
> >
> > Michael S. Tsirkin (1):
> >    ptr_ring: add ptr_ring_unconsume
> >
> >   drivers/net/tap.c         |  25 +++++++--
> >   drivers/net/tun.c         |  31 ++++++++---
> >   drivers/vhost/net.c       | 128 +++++++++++++++++++++++++++++++++++++++++++---
> >   include/linux/if_tap.h    |   5 ++
> >   include/linux/if_tun.h    |   5 ++
> >   include/linux/ptr_ring.h  | 120 +++++++++++++++++++++++++++++++++++++++++++
> >   include/linux/skb_array.h |  31 +++++++++++
> >   7 files changed, 327 insertions(+), 18 deletions(-)
> >
> > --
> > 2.7.4