[PATCH v2 net-next 0/2] account for TCP memory pressure signaled by cgroup

[Daniel Sedlak <daniel.sedlak@cdn77.com>]

Greetings kernel wizards,

To summarize from the commit messages, the attached patches are the
result of our recent debugging sessions, where we were hunting sudden
TCP network throughput drops, where the throughput dropped from tens of
Gbps to a few Mbps for an undeterministic amount of time.

The first patch adds a new counter for netstat, so users can notice that
the sockets are marked as under pressure. The second patch adds a new
tracepoint so it is easier to pinpoint which exact cgroup is having
difficulties.

Individual commit messages should contain more detailed reasoning.

Thanks!
Daniel

Changes:

v1 -> v2:
Add tracepoint
Link: https://lore.kernel.org/netdev/20250707105205.222558-1-daniel.sedlak@cdn77.com/

Daniel Sedlak (1):
  tcp: account for memory pressure signaled by cgroup

Matyas Hurtik (1):
  mm/vmpressure: add tracepoint for socket pressure detection

 .../networking/net_cachelines/snmp.rst        |  1 +
 include/net/tcp.h                             | 14 ++++++-----
 include/trace/events/memcg.h                  | 25 +++++++++++++++++++
 include/uapi/linux/snmp.h                     |  1 +
 mm/vmpressure.c                               |  3 +++
 net/ipv4/proc.c                               |  1 +
 6 files changed, 39 insertions(+), 6 deletions(-)

cc: linux-trace-kernel@vger.kernel.org
cc: linux-doc@vger.kernel.org
cc: Steven Rostedt <rostedt@goodmis.org>
cc: Masami Hiramatsu <mhiramat@kernel.org>
cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

base-commit: e96ee511c906c59b7c4e6efd9d9b33917730e000
-- 
2.39.5