[PATCH bpf-next 0/2] Remove unnecessary synchronizations in cpumap

[Hou Tao <houtao@huaweicloud.com>]

From: Hou Tao <houtao1@huawei.com>

Hi,

This is the formal patchset to remove unnecessary synchronizations in
cpu-map after address comments and collect Rvb tags from Toke
Høiland-Jørgensen (Big thanks to Toke). Patch #1 removes the unnecessary
rcu_barrier() when freeing bpf_cpu_map_entry and replaces it by
queue_rcu_work(). Patch #2 removes the unnecessary call_rcu() and
queue_work() when destroying cpu-map and does the freeing directly.

Test the patchset by using xdp_redirect_cpu and virtio-net. Both
xdp-mode and skb-mode have been exercised and no issues were reported.
As ususal, comments and suggestions are always welcome.

Change Log:
v1:
  * address comments from Toke Høiland-Jørgensen
  * add Rvb tags from Toke Høiland-Jørgensen
  * update outdated comment in cpu_map_delete_elem()

RFC: https://lore.kernel.org/bpf/20230728023030.1906124-1-houtao@huaweicloud.com

Hou Tao (2):
  bpf, cpumap: Use queue_rcu_work() to remove unnecessary rcu_barrier()
  bpf, cpumask: Clean up bpf_cpu_map_entry directly in cpu_map_free

 kernel/bpf/cpumap.c | 113 ++++++++++++++------------------------------
 1 file changed, 35 insertions(+), 78 deletions(-)

-- 
2.29.2