| Message ID | 20180912031709.14112-1-jasowang@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | vhost_net TX batching | expand |
From: Jason Wang <jasowang@redhat.com> Date: Wed, 12 Sep 2018 11:16:58 +0800 > This series tries to batch submitting packets to underlayer socket > through msg_control during sendmsg(). This is done by: ... Series applied, thanks Jason.
On Thu, Sep 13, 2018 at 09:28:19AM -0700, David Miller wrote: > From: Jason Wang <jasowang@redhat.com> > Date: Wed, 12 Sep 2018 11:16:58 +0800 > > > This series tries to batch submitting packets to underlayer socket > > through msg_control during sendmsg(). This is done by: > ... > > Series applied, thanks Jason. Going over it now I don't see a lot to complain about, but I'd appreciate a bit more time for review in the future. 3 days ok?
From: "Michael S. Tsirkin" <mst@redhat.com> Date: Thu, 13 Sep 2018 14:02:13 -0400 > On Thu, Sep 13, 2018 at 09:28:19AM -0700, David Miller wrote: >> From: Jason Wang <jasowang@redhat.com> >> Date: Wed, 12 Sep 2018 11:16:58 +0800 >> >> > This series tries to batch submitting packets to underlayer socket >> > through msg_control during sendmsg(). This is done by: >> ... >> >> Series applied, thanks Jason. > > Going over it now I don't see a lot to complain about, but I'd > appreciate a bit more time for review in the future. 3 days ok? I try to handle every patchwork entry within 48 hours, more specifically 2 business days. Given the rate at which patches flow through networking, I think this is both reasonable and necessary. One always have the option to send a quick reply to the list saying "Please wait for my review, I'll get to it in the next day or two." which I will certainly honor. Thank you.
Hi all: This series tries to batch submitting packets to underlayer socket through msg_control during sendmsg(). This is done by: 1) Doing userspace copy inside vhost_net 2) Build XDP buff 3) Batch at most 64 (VHOST_NET_BATCH) XDP buffs and submit them once through msg_control during sendmsg(). 4) Underlayer sockets can use XDP buffs directly when XDP is enalbed, or build skb based on XDP buff. For the packet that can not be built easily with XDP or for the case that batch submission is hard (e.g sndbuf is limited). We will go for the previous slow path, passing iov iterator to underlayer socket through sendmsg() once per packet. This can help to improve cache utilization and avoid lots of indirect calls with sendmsg(). It can also co-operate with the batching support of the underlayer sockets (e.g the case of XDP redirection through maps). Testpmd(txonly) in guest shows obvious improvements: Test /+pps% XDP_DROP on TAP /+44.8% XDP_REDIRECT on TAP /+29% macvtap (skb) /+26% Netperf TCP_STREAM TX from guest shows obvious improvements on small packet: size/session/+thu%/+normalize% 64/ 1/ +2%/ 0% 64/ 2/ +3%/ +1% 64/ 4/ +7%/ +5% 64/ 8/ +8%/ +6% 256/ 1/ +3%/ 0% 256/ 2/ +10%/ +7% 256/ 4/ +26%/ +22% 256/ 8/ +27%/ +23% 512/ 1/ +3%/ +2% 512/ 2/ +19%/ +14% 512/ 4/ +43%/ +40% 512/ 8/ +45%/ +41% 1024/ 1/ +4%/ 0% 1024/ 2/ +27%/ +21% 1024/ 4/ +38%/ +73% 1024/ 8/ +15%/ +24% 2048/ 1/ +10%/ +7% 2048/ 2/ +16%/ +12% 2048/ 4/ 0%/ +2% 2048/ 8/ 0%/ +2% 4096/ 1/ +36%/ +60% 4096/ 2/ -11%/ -26% 4096/ 4/ 0%/ +14% 4096/ 8/ 0%/ +4% 16384/ 1/ -1%/ +5% 16384/ 2/ 0%/ +2% 16384/ 4/ 0%/ -3% 16384/ 8/ 0%/ +4% 65535/ 1/ 0%/ +10% 65535/ 2/ 0%/ +8% 65535/ 4/ 0%/ +1% 65535/ 8/ 0%/ +3% Please review. Thanks Changes from V1: - don't hold page refcnt for XDP_DROP - release page if build_skb() fails - introduce a helper to build skb for the path of no batching mode - rename tun_do_xdp() as tun_xdp_act() and use negative for reporting errors instead of a pointer to integer - introduce a num field in tun_msg_ctl - introduce a new structure for storing metadata in the head of XDP packet - do not store batche XDP inside vhoet_net_virtqueue Jason Wang (11): net: sock: introduce SOCK_XDP tuntap: switch to use XDP_PACKET_HEADROOM tuntap: enable bh early during processing XDP tuntap: simplify error handling in tun_build_skb() tuntap: tweak on the path of skb XDP case in tun_build_skb() tuntap: split out XDP logic tuntap: move XDP flushing out of tun_do_xdp() tun: switch to new type of msg_control tuntap: accept an array of XDP buffs through sendmsg() tap: accept an array of XDP buffs through sendmsg() vhost_net: batch submitting XDP buffers to underlayer sockets drivers/net/tap.c | 88 +++++++++++++- drivers/net/tun.c | 267 ++++++++++++++++++++++++++++++++--------- drivers/vhost/net.c | 181 +++++++++++++++++++++++++--- include/linux/if_tun.h | 14 +++ include/net/sock.h | 1 + 5 files changed, 471 insertions(+), 80 deletions(-)