[bpf-next,0/2] load-acquire/store-release semantics for AF_XDP rings

Message

Björn Töpel March 1, 2021, 10:43 a.m. UTC

This two-patch series introduces load-acquire/store-release semantics
for the AF_XDP rings.

For most contemporary architectures, this is more effective than a
SPSC ring based on smp_{r,w,}mb() barriers. More importantly,
load-acquire/store-release semantics make the ring code easier to
follow.

This is effectively the change done in commit 6c43c091bdc5
("documentation: Update circular buffer for
load-acquire/store-release"), but for the AF_XDP rings.

Both libbpf and the kernel-side are updated.

More details in each commit.


Thanks,
Björn


Björn Töpel (2):
  xsk: update rings for load-acquire/store-release semantics
  libbpf, xsk: add libbpf_smp_store_release libbpf_smp_load_acquire

 net/xdp/xsk_queue.h         | 27 ++++++--------
 tools/lib/bpf/libbpf_util.h | 72 +++++++++++++++++++++++++------------
 tools/lib/bpf/xsk.h         | 17 +++------
 3 files changed, 66 insertions(+), 50 deletions(-)


base-commit: 85e142cb42a1e7b33971bf035dae432d8670c46b