[RFC,0/2] net: introduce per netns packet type chains

Message

Paolo Abeni March 14, 2025, 1:04 p.m. UTC

The stack uses shared lists between all the network namespace to store
all the packet taps not bound to any device.

As a consequence, creating such taps in any namespace affects the
performances in all the network namespaces.

Patch 1 addresses the issue introducing new per network namespace packet
type chains, while patch 2 try to minimize the impact of such addition.

The hotdata implications are IMHO not trivial ence the RFC tag; I
suspect patch 2 being the most controversial. As such a possible
alternative is also presented.

Any feedback welcome!

Paolo Abeni (2):
  net: introduce per netns packet chains
  net: hotdata optimization for netns ptypes

 .../networking/net_cachelines/net_device.rst  |  2 +
 include/linux/netdevice.h                     |  9 +-
 include/net/hotdata.h                         |  1 -
 include/net/net_namespace.h                   |  3 +
 net/core/dev.c                                | 82 +++++++++++++++----
 net/core/hotdata.c                            |  1 -
 net/core/net-procfs.c                         | 16 ++--
 net/core/net_namespace.c                      |  2 +
 8 files changed, 86 insertions(+), 30 deletions(-)