linux/net/ipv4
Fred Klassen 76e21533a4 net/udp_gso: Allow TX timestamp with UDP GSO
Fixes an issue where TX Timestamps are not arriving on the error queue
when UDP_SEGMENT CMSG type is combined with CMSG type SO_TIMESTAMPING.
This can be illustrated with an updated updgso_bench_tx program which
includes the '-T' option to test for this condition. It also introduces
the '-P' option which will call poll() before reading the error queue.

    ./udpgso_bench_tx -4ucTPv -S 1472 -l2 -D 172.16.120.18
    poll timeout
    udp tx:      0 MB/s        1 calls/s      1 msg/s

The "poll timeout" message above indicates that TX timestamp never
arrived.

This patch preserves tx_flags for the first UDP GSO segment. Only the
first segment is timestamped, even though in some cases there may be
benefital in timestamping both the first and last segment.

Factors in deciding on first segment timestamp only:

- Timestamping both first and last segmented is not feasible. Hardware
can only have one outstanding TS request at a time.

- Timestamping last segment may under report network latency of the
previous segments. Even though the doorbell is suppressed, the ring
producer counter has been incremented.

- Timestamping the first segment has the upside in that it reports
timestamps from the application's view, e.g. RTT.

- Timestamping the first segment has the downside that it may
underreport tx host network latency. It appears that we have to pick
one or the other. And possibly follow-up with a config flag to choose
behavior.

v2: Remove tests as noted by Willem de Bruijn <willemb@google.com>
    Moving tests from net to net-next

v3: Update only relevant tx_flag bits as per
    Willem de Bruijn <willemb@google.com>

v4: Update comments and commit message as per
    Willem de Bruijn <willemb@google.com>

Fixes: ee80d1ebe5 ("udp: add udp gso")
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-18 21:38:07 -04:00
..
bpfilter SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2019-05-23 14:45:36 -07:00
af_inet.c SPDX update for 5.2-rc3, round 1 2019-05-31 08:34:32 -07:00
ah4.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
arp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cipso_ipv4.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
datagram.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
devinet.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
esp4.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
esp4_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422 2019-06-05 17:37:15 +02:00
fib_frontend.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fib_lookup.h ipv4: Add fib_nh_common to fib_result 2019-04-03 21:50:20 -07:00
fib_notifier.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_rules.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fib_semantics.c net: ipv4: fib_semantics: fix uninitialized variable 2019-06-09 12:47:30 -07:00
fib_trie.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fou.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
gre_demux.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
gre_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
icmp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
igmp.c SPDX update for 5.2-rc3, round 1 2019-05-31 08:34:32 -07:00
inet_connection_sock.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_fragment.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_hashtables.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_timewait_sock.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
inetpeer.c net: ipv4: use a dedicated counter for icmp_v4 redirect packets 2019-02-08 21:50:15 -08:00
ip_forward.c ipv4: Prepare rtable for IPv6 gateway 2019-04-08 15:22:40 -07:00
ip_fragment.c net: remove unused struct inet_frag_queue.fragments field 2019-02-26 08:27:05 -08:00
ip_gre.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ip_input.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ip_options.c vrf: check accept_source_route on the original netdevice 2019-04-01 10:44:58 -07:00
ip_output.c net: correct udp zerocopy refcnt also when zerocopy only on append 2019-06-11 11:40:54 -07:00
ip_sockglue.c ip_sockglue: Fix missing-check bug in ip_ra_control() 2019-05-25 11:00:50 -07:00
ip_tunnel.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269 2019-06-05 17:30:29 +02:00
ip_tunnel_core.c ip_tunnel: allow not to count pkts on tstats by setting skb's dev to NULL 2019-06-18 20:48:45 -04:00
ip_vti.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipcomp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipconfig.c ipconfig: add carrier_timeout kernel parameter 2019-02-01 15:24:13 -08:00
ipip.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipmr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipmr_base.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-07 17:22:09 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile xfrm: make xfrm modes builtin 2019-04-08 09:15:17 +02:00
metrics.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
netfilter.c netfilter: ipv4: remove useless export_symbol 2019-01-28 11:32:58 +01:00
netlink.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
ping.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
proc.c tcp: tcp_fragment() should apply sane memory limits 2019-06-15 18:47:31 -07:00
protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
raw.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
raw_diag.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 09:29:14 -07:00
syncookies.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sysctl_net_ipv4.c Merge branch 'tcp-fixes' 2019-06-17 10:39:56 -07:00
tcp.c Merge branch 'tcp-fixes' 2019-06-17 10:39:56 -07:00
tcp_bbr.c tcp_bbr: adapt cwnd based on ack aggregation estimation 2019-01-24 22:27:27 -08:00
tcp_bic.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_bpf.c bpf, tcp: correctly handle DONT_WAIT flags and timeo == 0 2019-05-16 01:36:13 +02:00
tcp_cdg.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_cong.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_cubic.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_dctcp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_dctcp.h tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
tcp_diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_fastopen.c tcp: pause Fast Open globally after third consecutive timeout 2017-12-13 15:51:12 -05:00
tcp_highspeed.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_htcp.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_hybla.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_illinois.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_input.c tcp: limit payload size of sacked skbs 2019-06-15 18:47:31 -07:00
tcp_ipv4.c tcp: add tcp_min_snd_mss sysctl 2019-06-15 18:47:31 -07:00
tcp_lp.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_metrics.c tcp: refactor setting the initial congestion window 2019-05-01 11:47:54 -04:00
tcp_minisocks.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_nv.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_output.c tcp: add tcp_min_snd_mss sysctl 2019-06-15 18:47:31 -07:00
tcp_rate.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_recovery.c tcp: introduce tcp_skb_timestamp_us() helper 2018-09-21 19:37:59 -07:00
tcp_scalable.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_timer.c tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() 2019-06-15 18:47:31 -07:00
tcp_ulp.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_vegas.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_vegas.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_veno.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_westwood.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_yeah.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tunnel4.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
udp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-06-07 14:46:47 -07:00
udp_diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
udp_impl.h udp: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
udp_offload.c net/udp_gso: Allow TX timestamp with UDP GSO 2019-06-18 21:38:07 -04:00
udp_tunnel.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
udplite.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm4_input.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_output.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm4_policy.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2019-04-30 09:26:13 -04:00
xfrm4_protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm4_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm4_tunnel.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00