This patch series completes the removal of rte_smp_XX barrier functions that was announced over five years ago (20.05).
In the process several cases of race conditions were found and fixed. See patches 3, 4, and 17. These are marked with Fixes: tags and Cc: stable. Patch 2 is also marked for stable because 3 and 4 do not build with clang without it. Most of this is mechanical with AI assistance, so strongly encourage maintainers to take a good look. Functional and build run on x86 and ARM native. Barriers ordering memory writes against a device doorbell now use rte_io_wmb() rather than an SMP barrier; on arm64 that is dmb oshst instead of dmb ishst. In some cases the C11 form gives marginal performance gains. The lock-free stack patch measured faster than the generic version it replaces, up to 63% on a 32-core x86 box; the numbers are in that patch's commit message. The RFC removed the barrier test outright. Konstantin pointed out it still covers the custom x86 seq_cst fence, so patch 19 now keeps the Peterson lock test and converts it to C11 atomics instead, with the fence and rte_mb() as its two cases. It comes before the x86 patch that drops rte_smp_mb(), since it holds the last caller and x86 builds with tests enabled would otherwise break for the rest of the series. As a side note, Konstantin asked whether the two versions of __rte_ring_headtail_move_head_st() could be merged into one, keeping only the _mt variants separate. That looks reasonable but is out of scope here; left for a follow-up. v3 - rebase - address review feedback - detailed review of bpf change - reword overly verbose AI verbiage - combine patches where possible Stephen Hemminger (29): bpf: replace deprecated SMP barriers with C11 fences bus/vmbus: remove packed attribute from ring buffer bus/vmbus: fix ring buffer ordering on weakly ordered CPUs bus/vmbus: fix missing acquire on receive ring index bus/vmbus: replace SMP barriers with C11 memory fences drivers/baseband: convert rte_smp_rmb to fence net/hinic: replace rte_smp_rmb net/intel: replace rte_smp_rmb net/virtio: replace rte_smp_rmb net/thunderx: replace deprecated SMP barriers stack: always use C11 memory model implementation ring: replace SMP read barrier with C11 acquire fence crypto/virtio: update comment reference to rte_smp_rmb crypto/caam_jr: replace rte_smp_rmb crypto/caam_jr: use IO barrier before job ring doorbell crypto/octeontx: use IO barrier before doorbell event/sw: fix unlinks in progress counter races event/sw: replace SMP barriers with C11 atomics test/barrier: convert to C11 atomics eal/x86: move optimized fence out of SMP barrier common/octeontx: remove redundant barrier in mbox mempool/octeontx: use IO barrier in pool destroy event/octeontx: replace deprecated SMP barriers event/dpaa2: replace deprecated barrier in selftest event/dsw: replace SMP barriers with release fences event/opdl: replace SMP barriers with C11 atomics net/virtio: replace deprecated barrier in avail index update eal: remove stale SMP barrier in rte_service eal: remove rte_smp_XX app/test/test_barrier.c | 71 ++++---- devtools/checkpatches.sh | 8 - doc/guides/rel_notes/deprecation.rst | 8 - doc/guides/rel_notes/release_26_11.rst | 11 ++ .../fpga_5gnr_fec/rte_fpga_5gnr_fec.c | 8 +- drivers/baseband/fpga_lte_fec/fpga_lte_fec.c | 12 +- drivers/bus/vmbus/private.h | 12 +- drivers/bus/vmbus/rte_vmbus_reg.h | 4 +- drivers/bus/vmbus/vmbus_bufring.c | 22 +-- drivers/bus/vmbus/vmbus_channel.c | 13 +- drivers/common/octeontx/octeontx_mbox.c | 6 +- drivers/crypto/caam_jr/caam_jr.c | 5 +- .../crypto/octeontx/otx_cryptodev_hw_access.h | 4 +- drivers/crypto/virtio/virtqueue.h | 8 +- drivers/event/dpaa2/dpaa2_eventdev_selftest.c | 4 +- drivers/event/dsw/dsw_event.c | 8 +- drivers/event/octeontx/ssovf_evdev_selftest.c | 6 +- drivers/event/octeontx/ssovf_worker.c | 8 +- drivers/event/opdl/opdl_evdev.c | 8 +- drivers/event/sw/sw_evdev.c | 37 +++-- drivers/event/sw/sw_evdev.h | 2 +- drivers/event/sw/sw_evdev_scheduler.c | 24 ++- drivers/mempool/octeontx/octeontx_fpavf.c | 4 +- drivers/net/hinic/base/hinic_pmd_cmdq.c | 3 +- drivers/net/hinic/base/hinic_pmd_mgmt.c | 2 +- drivers/net/intel/ice/ice_rxtx.c | 2 +- drivers/net/intel/ixgbe/ixgbe_rxtx.c | 2 +- drivers/net/thunderx/base/nicvf_hw.c | 3 +- drivers/net/thunderx/base/nicvf_plat.h | 5 +- drivers/net/virtio/virtqueue.h | 22 +-- lib/bpf/bpf_pkt.c | 45 ++++-- lib/eal/arm/include/rte_atomic_32.h | 6 - lib/eal/arm/include/rte_atomic_64.h | 6 - lib/eal/common/rte_service.c | 1 - lib/eal/include/generic/rte_atomic.h | 61 ------- lib/eal/loongarch/include/rte_atomic.h | 6 - lib/eal/ppc/include/rte_atomic.h | 6 - lib/eal/riscv/include/rte_atomic.h | 6 - lib/eal/x86/include/rte_atomic.h | 41 ++--- lib/ring/rte_ring_gcc_pvt.h | 6 +- lib/stack/meson.build | 1 - lib/stack/rte_stack_lf.h | 4 - lib/stack/rte_stack_lf_generic.h | 153 ------------------ 43 files changed, 237 insertions(+), 437 deletions(-) delete mode 100644 lib/stack/rte_stack_lf_generic.h -- 2.53.0
