[net-next,v2,00/18] net: Cover more per-CPU storage with local nested BH locking.

Message

Sebastian Andrzej Siewior April 14, 2025, 4:07 p.m. UTC

I was looking at the build-time defined per-CPU variables in net/ and
added the needed local-BH-locks in order to be able to remove the
current per-CPU lock in local_bh_disable() on PREMPT_RT.

The work is not yet complete, I just wanted to post what I have so far
instead of sitting on it.

v1…v2: https://lore.kernel.org/all/[e-mail]
    - act_mirred: Using proper variable on PREEMPT_RT, noticed by Davide
      Caratti.
    - openvswitch:
      - Renamed the per-CPU variable to ovs_pcpu_storage.
      - Moved some data structures from action.c to datapath.h in order
        to implement the locking within datapath.c.

Sebastian Andrzej Siewior (18):
  net: page_pool: Don't recycle into cache on PREEMPT_RT
  net: dst_cache: Use nested-BH locking for dst_cache::cache
  ipv4/route: Use this_cpu_inc() for stats on PREEMPT_RT
  ipv6: sr: Use nested-BH locking for hmac_storage
  xdp: Use nested-BH locking for system_page_pool
  netfilter: nf_dup{4, 6}: Move duplication check to task_struct
  netfilter: nft_inner: Use nested-BH locking for nft_pcpu_tun_ctx
  netfilter: nf_dup_netdev: Move the recursion counter struct
    netdev_xmit
  xfrm: Use nested-BH locking for nat_keepalive_sk_ipv[46]
  openvswitch: Merge three per-CPU structures into one
  openvswitch: Use nested-BH locking for ovs_pcpu_storage
  openvswitch: Move ovs_frag_data_storage into the struct
    ovs_pcpu_storage
  net/sched: act_mirred: Move the recursion counter struct netdev_xmit
  net/sched: Use nested-BH locking for sch_frag_data_storage
  mptcp: Use nested-BH locking for hmac_storage
  rds: Disable only bottom halves in rds_page_remainder_alloc()
  rds: Acquire per-CPU pointer within BH disabled section
  rds: Use nested-BH locking for rds_page_remainder

 include/linux/netdevice.h        |  7 ++-
 include/linux/netdevice_xmit.h   |  6 +++
 include/linux/netfilter.h        | 11 ----
 include/linux/sched.h            |  1 +
 net/core/dev.c                   | 15 ++++--
 net/core/dst_cache.c             | 30 +++++++++--
 net/core/page_pool.c             |  4 ++
 net/core/xdp.c                   | 11 +++-
 net/ipv4/netfilter/ip_tables.c   |  2 +-
 net/ipv4/netfilter/nf_dup_ipv4.c |  6 +--
 net/ipv4/route.c                 |  4 ++
 net/ipv6/netfilter/ip6_tables.c  |  2 +-
 net/ipv6/netfilter/nf_dup_ipv6.c |  6 +--
 net/ipv6/seg6_hmac.c             | 13 ++++-
 net/mptcp/protocol.c             |  4 +-
 net/mptcp/protocol.h             |  9 +++-
 net/netfilter/core.c             |  3 --
 net/netfilter/nf_dup_netdev.c    | 22 ++++++--
 net/netfilter/nft_inner.c        | 18 +++++--
 net/openvswitch/actions.c        | 86 +++++---------------------------
 net/openvswitch/datapath.c       | 28 ++++++++---
 net/openvswitch/datapath.h       | 52 +++++++++++++++++--
 net/rds/page.c                   | 25 ++++++----
 net/sched/act_mirred.c           | 28 +++++++++--
 net/sched/sch_frag.c             | 10 +++-
 net/xfrm/xfrm_nat_keepalive.c    | 30 +++++++----
 26 files changed, 280 insertions(+), 153 deletions(-)