net/smc: Add net namespace for tracepoints

This prints net namespace ID, helps us to distinguish different net
namespaces when using tracepoints.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc: Print function name in smcr_link_down tracepoint

This makes the output of smcr_link_down tracepoint easier to use and
understand without additional translating function's pointer address.

It prints the function name with offset:

<idle>-0 [000] ..s. 69.087164: smcr_link_down: lnk=00000000dab41cdc lgr=000000007d5d8e24 state=0 rc=1 dev=mlx5_0 location=smc_wr_tx_tasklet_fn+0x5ef/0x6f0 [smc]

Link: https://lore.kernel.org/netdev/11f17a34-fd35-f2ec-3f20-dd0c34e55fde@linux.ibm.com/
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc: Introduce tracepoint for smcr link down

SMC-R link down event is important to help us find links' issues, we
should track this event, especially in the single nic mode, which means
upper layer connection would be shut down. Then find out the direct
link-down reason in time, not only increased the counter, also the
location of the code who triggered this event.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc: Introduce tracepoints for tx and rx msg

This introduce two tracepoints for smc tx and rx msg to help us
diagnosis issues of data path. These two tracepoitns don't cover the
path of CORK or MSG_MORE in tx, just the top half of data path.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc: Introduce tracepoint for fallback

This introduces tracepoint for smc fallback to TCP, so that we can track
which connection and why it fallbacks, and map the clcsocks' pointer with
/proc/net/tcp to find more details about TCP connections. Compared with
kprobe or other dynamic tracing, tracepoints are stable and easy to use.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>