在 2021/4/20 上午12:48, David Ahern 写道:
On 4/16/21 2:16 AM, Xuan Zhuo wrote:In page_to_skb(), if we have enough tailroom to save skb_shared_info, we can use build_skb to create skb directly. No need to alloc for additional space. And it can save a 'frags slot', which is very friendly to GRO. Here, if the payload of the received package is too small (less than GOOD_COPY_LEN), we still choose to copy it directly to the space got by napi_alloc_skb. So we can reuse these pages. Testing Machine: The four queues of the network card are bound to the cpu1. Test command: for ((i=0;i<5;++i)); do sockperf tp --ip 192.168.122.64 -m 1000 -t 150& done The size of the udp package is 1000, so in the case of this patch, there will always be enough tailroom to use build_skb. The sent udp packet will be discarded because there is no port to receive it. The irqsoftd of the machine is 100%, we observe the received quantity displayed by sar -n DEV 1: no build_skb: 956864.00 rxpck/s build_skb: 1158465.00 rxpck/svirtio_net is using napi_consume_skb, so napi_build_skb should show a small increase from build_skb.
Yes and we probably need to do this in receive_small(). Thanks _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
