From: Jia Jia <[email protected]> This series reduces per-packet socket overhead in the virtio-vsock RX worker.
Patch 1: separate socket lookup from locked packet processing. Patch 2: keep one socket lock across a bounded run of established STREAM/RW packets for the same native socket. Patch 3: reuse the locked socket for later packets with the same address tuple. Patch 4: coalesce default write-space notifications while that lock is held. Patch 5: defer the default readable callback until after the batch unlocks. Custom callbacks retain per-packet notification behavior. Performance: Tested on single-stream AF_VSOCK (1 reader on Guest CPU0, virtio-vsock IRQ on Guest CPU1, fresh QEMU guest per state, 16 balanced AB/BA pairs per payload). End-to-end RX throughput (64K receiver buffer, SO_RCVLOWAT=1): payload baseline RX (G/s) PATCH RX (G/s) throughput change (95% CI) 256B 0.5722 1.0286 +79.76% [+75.40%, +84.23%] 512B 1.1464 1.9779 +72.53% [+69.50%, +75.63%] 1K 2.2714 3.6368 +60.12% [+56.92%, +63.37%] 4K 3.9095 7.7160 +97.37% [+92.09%, +102.79%] Fixed-syscall stress test (receiver buffer = sender write size; RX in G/s): payload baseline RX PATCH RX throughput change (95% CI) recv() base/patch 256B 0.2885 0.6737 +133.50% [+123.58%, +143.86%] 1048577/1048577 512B 0.5631 1.2091 +114.71% [+104.97%, +124.92%] 1048577/1048577 1K 1.5361 2.9678 +93.20% [+80.15%, +107.20%] 1048577/1048577 4K 2.8378 6.1878 +118.05% [+109.15%, +127.33%] 538802/525645 Request-response latency (Ping-Pong RTT, 10,000 requests): payload baseline mean RTT (us) PATCH mean RTT (us) change (95% CI) 256B 126.968 124.541 -1.91% [-3.35%, -0.45%] 4K 130.362 126.664 -2.84% [-5.12%, -0.50%] Diagnostic Guest CPU1 system-wide cycles (fixed-64K receiver, with perf): Buffer size baseline cycles/B PATCH cycles/B cycles change (95% CI) 256B 15.287 13.630 -10.84% [-12.51%, -9.14%] 512B 7.306 6.611 -9.51% [-10.92%, -8.08%] 1K 3.811 3.458 -9.25% [-10.96%, -7.50%] 4K 1.850 1.669 -9.75% [-11.78%, -7.67%] Jia Jia (5): vsock: split socket lookup from locked RX processing vsock: amortize RX socket locking for stream packets vsock: reuse same-flow socket lookup in RX batches vsock: coalesce RX write-space notifications in lock batches vsock: defer RX readable notifications until batch unlock include/linux/virtio_vsock.h | 14 ++ include/net/af_vsock.h | 3 + net/vmw_vsock/af_vsock.c | 2 + net/vmw_vsock/virtio_transport.c | 48 ++++- net/vmw_vsock/virtio_transport_common.c | 341 +++++++++++++++++++++++++++----- 5 files changed, 357 insertions(+), 51 deletions(-) base-commit: f5f84daefcd92d7a630066635ecea1433ed5eac7 -- 2.53.0
