This test occasionally fails due to exceeding timing bounds, as
run in continuous testing on netdev.bots:
https://netdev.bots.linux.dev/contest.html?test=txtimestamp-sh
A common pattern is a single elevated delay between USR and SND.
# 8.36 [+0.00] test SND
# 8.36 [+0.00] USR: 1767864384 s 240994 us (seq=0, len=0)
# 8.44 [+0.08] ERROR: 18461 us expected between 10000 and 18000
# 8.44 [+0.00] SND: 1767864384 s 259455 us (seq=42, len=10) (USR +18460 us)
# 8.52 [+0.07] SND: 1767864384 s 339523 us (seq=42, len=10) (USR +10005 us)
# 8.52 [+0.00] USR: 1767864384 s 409580 us (seq=0, len=0)
# 8.60 [+0.08] SND: 1767864384 s 419586 us (seq=42, len=10) (USR +10005 us)
# 8.60 [+0.00] USR: 1767864384 s 489645 us (seq=0, len=0)
# 8.68 [+0.08] SND: 1767864384 s 499651 us (seq=42, len=10) (USR +10005 us)
# 8.68 [+0.00] USR-SND: count=4, avg=12119 us, min=10005 us, max=18460 us
(Note that other delays are nowhere near the large 8ms tolerance.)
One hypothesis is that the task is descheduled between taking the USR
timestamp and sending the packet. Possibly in printing.
Delay taking the timestamp closer to sendmsg, and delay printing until
after sendmsg.
With this change, failure rate is significantly lower in current runs.
Link: https://lore.kernel.org/netdev/20260107110521.1aab55e9@kernel.org/
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260112163355.3510150-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
char variable in 'so_txtime.c' & 'txtimestamp.c' were left uninitilized
when switch default case taken. which raises following warning.
txtimestamp.c:240:2: warning: variable 'tsname' is used uninitialized
whenever switch default is taken [-Wsometimes-uninitialized]
so_txtime.c:210:3: warning: variable 'reason' is used uninitialized
whenever switch default is taken [-Wsometimes-uninitialized]
initializing these variables to NULL to fix this.
Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux@gmail.com>
Link: https://patch.msgid.link/20251125165302.20079-1-ankitkhushwaha.linux@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When I was trying to modify the tx timestamping feature, I found that
running "./txtimestamp -4 -C -L 127.0.0.1" didn't reflect the error:
I succeeded to generate timestamp stored in the skb but later failed
to report it to the userspace (which means failed to put css into cmsg).
It can happen when someone writes buggy codes in __sock_recv_timestamp(),
for example.
After adding the check so that running ./txtimestamp will reflect the
result correctly like this if there is a bug in the reporting phase:
protocol: TCP
payload: 10
server port: 9000
family: INET
test SND
USR: 1725458477 s 667997 us (seq=0, len=0)
Failed to report timestamps
USR: 1725458477 s 718128 us (seq=0, len=0)
Failed to report timestamps
USR: 1725458477 s 768273 us (seq=0, len=0)
Failed to report timestamps
USR: 1725458477 s 818416 us (seq=0, len=0)
Failed to report timestamps
...
In the future, it will help us detect whether the new coming patch has
bugs or not.
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240905160035.62407-1-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This test is time sensitive. It may fail on virtual machines and for
debug builds.
Similar to commit c41dfb0dfb ("selftests/net: ignore timing errors in
so_txtime if KSFT_MACHINE_SLOW"), optionally suppress failure for timing
errors (only).
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The txtimestamp selftest sets a fixed 500us tolerance. This value was
arrived at experimentally. Some platforms have higher variances. Make
this adjustable by adding the following flag:
-t N: tolerance (usec) for timestamp validation.
Signed-off-by: Jian Yang <jianyang@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For historical reasons, there are several timestamping selftest targets
in selftests/networking/timestamping. Move them to the standard
directory for networking tests: selftests/net.
Signed-off-by: Jian Yang <jianyang@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
