On Tue, May 28, 2019 at 3:10 PM Fred Klassen fklassen@appneta.com wrote:
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.
./udpgso_bench_tx -4ucTPv -S 1472 -l2 -D 172.16.120.18 poll timeout udp tx: 0 MB/s 1 calls/s 1 msg/sThe "poll timeout" message above indicates that TX timestamp never arrived.
It also appears that other TX CMSG types cause similar issues, for example trying to set SOL_IP/IP_TOS.
See previous comment in v2
http://patchwork.ozlabs.org/patch/1105564/
./udpgso_bench_tx -4ucPv -S 1472 -q 182 -l2 -D 172.16.120.18 poll timeout udp tx: 0 MB/s 1 calls/s 1 msg/sThis patch preserves tx_flags for the first UDP GSO segment.
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
Fixes: ee80d1ebe5ba ("udp: add udp gso") Signed-off-by: Fred Klassen fklassen@appneta.com
FYI, no need for a cover letter for a single patch. Also, I think the cc list can be more concise. Mainly netdev.
net/ipv4/udp_offload.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 065334b41d57..de8ecba42d55 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -228,6 +228,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, seg = segs; uh = udp_hdr(seg);
/* preserve TX timestamp and zero-copy info for first segment */
Same as above. This is not about zerocopy.
skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey;skb_shinfo(seg)->tx_flags |=(skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP);
Asked elsewhere, but best answered here: given that xmit_more delays delivery to the NIC until the last segment in a train, is the first segment in your opinion still the best to attach the timestamp request to?
To reiterate, we do not want to need a follow-up patch to disable xmit_more when timestamps are requested.
/* compute checksum adjustment based on old length versus new */ newlen = htons(sizeof(*uh) + mss); check = csum16_add(csum16_sub(uh->check, uh->len), newlen);-- 2.11.0