From: Scott <[email protected]> This series fixes critical thread safety bugs in the af_packet PMD and adds performance optimizations.
Patch 1 fixes two major correctness issues: - Thread safety: tp_status was accessed without memory barriers, violating the kernel's PACKET_MMAP protocol. On aarch64 and other weakly-ordered architectures, this causes packet corruption due to missing memory ordering. The fix matches the kernel's memory model: volatile unaligned reads/writes with explicit rte_smp_rmb/wmb barriers and __may_alias__ protection. - Frame calculations: Fixed incorrect frame overhead and address calculations that caused memory corruption when frames don't evenly divide blocks. Patches 2-4 add performance improvements: - Patch 2: Bulk mbuf freeing, unlikely annotations, and prefetching - Patch 3: TX poll control to reduce syscall overhead - Patch 4: Software checksum offload support with shared rte_net utility v5 changes: - rte_net_ip_udptcp_cksum_mbuf moved to rte_net.c (avoid forced inline) - rte_net_ip_udptcp_cksum_mbuf remove copy arg, handle more mbuf types - af_packet and tap calling code consistent for sw cksum v4 changes: - Remove prefetch (perf results didn't show benefit) - Fix variable sytle for consistency (declare at start of method) - Add release notes for af_packet and documentation for fixes v3 changes: - Patch 4: Fix compile error due to implict cast with c++ compiler v2 changes: - Patch 1: Rewrote to use volatile + barriers instead of C11 atomics to match kernel's memory model. Added dependency on patch-160274 for __rte_may_alias attribute. - Patch 4: Refactored to use shared rte_net_ip_udptcp_cksum_mbuf() utility function, eliminating code duplication with tap driver. Scott Mitchell (4): net/af_packet: fix thread safety and frame calculations net/af_packet: RX/TX bulk free, unlikely hint net/af_packet: tx poll control net/af_packet: add software checksum offload support doc/guides/nics/af_packet.rst | 6 +- doc/guides/nics/features/afpacket.ini | 2 + doc/guides/rel_notes/release_26_03.rst | 7 + drivers/net/af_packet/rte_eth_af_packet.c | 253 +++++++++++++++------- drivers/net/tap/rte_eth_tap.c | 70 +----- lib/net/rte_net.c | 68 ++++++ lib/net/rte_net.h | 22 ++ 7 files changed, 287 insertions(+), 141 deletions(-) -- 2.39.5 (Apple Git-154)
