Now, virtio-net already supports per-queue moderation parameter setting. Based on this, we use the linux dimlib to support dynamic coalescing moderation for virtio-net.
Due to some scheduling issues, we only support and test the rx dim. Some test results: I. Sockperf UDP ================================================= 1. Env rxq_0 with affinity to cpu_0. 2. Cmd client: taskset -c 0 sockperf tp -p 8989 -i $IP -t 10 -m 16B server: taskset -c 0 sockperf sr -p 8989 3. Result dim off: 1143277.00 rxpps, throughput 17.844 MBps, cpu is 100%. dim on: 1124161.00 rxpps, throughput 17.610 MBps, cpu is 83.5%. ================================================= II. Redis ================================================= 1. Env There are 8 rxqs, and rxq_i with affinity to cpu_i. 2. Result When all cpus are 100%, ops/sec of memtier_benchmark client is dim off: 978437.23 dim on: 1143638.28 ================================================= III. Nginx ================================================= 1. Env There are 8 rxqs and rxq_i with affinity to cpu_i. 2. Result When all cpus are 100%, requests/sec of wrk client is dim off: 877931.67 dim on: 1019160.31 ================================================= IV. Latency of sockperf udp ================================================= 1. Rx cmd taskset -c 0 sockperf sr -p 8989 2. Tx cmd taskset -c 0 sockperf pp -i ${ip} -p 8989 -t 10 After running this cmd 5 times and averaging the results, 3. Result dim off: 17.7735 usec dim on: 18.0110 usec ================================================= Changelog: v6->v7: - Drop the patch titled "spin lock for ctrl cmd access" - Use rtnl_trylock to avoid the deadlock. v5->v6: - Add patch(4/5): spin lock for ctrl cmd access - Patch(5/5): - Use spin lock and cancel_work_sync to synchronize v4->v5: - Patch(4/4): - Fix possible synchronization issues with cancel_work_sync. - Reduce if/else nesting levels v3->v4: - Patch(5/5): drop. v2->v3: - Patch(4/5): some minor modifications. v1->v2: - Patch(2/5): a minor fix. - Patch(4/5): - improve the judgment of dim switch conditions. - Cancel the work when vq reset. - Patch(5/5): drop the tx dim implementation. Heng Qi (4): virtio-net: returns whether napi is complete virtio-net: separate rx/tx coalescing moderation cmds virtio-net: extract virtqueue coalescig cmd for reuse virtio-net: support rx netdim drivers/net/virtio_net.c | 297 ++++++++++++++++++++++++++++++++------- 1 file changed, 248 insertions(+), 49 deletions(-) -- 2.19.1.6.gb485710b