On Thu, 15 Aug 2024 19:23:50 +0000 Haiyang Zhang wrote: > Your suggestion on netif_get_num_default_rss_queues() is not ignored. > We discussed internally on the formula we used for the num_chn, and > chose a similar formula for higher number of vCPUs as in > netif_get_num_default_rss_queues(). > For lower number of vCPUs, we use the same default as Windows guests, > because we don't want any potential regression. Ideally you'd just use netif_get_num_default_rss_queues() but the code is close enough to that, and I don't have enough experience with the question of online CPUs vs physical CPUs. I would definitely advise you to try this on real workloads. While "iperf" looks great with a lot of rings, real workloads suffer measurably from having more channels eating up memory and generating interrupts. But if you're confident with the online_cpus() / 2, that's fine. You may be better off coding it up using max: dev_info->num_chn = max(DIV_ROUND_UP(num_online_cpus(), 2), VRSS_CHANNEL_DEFAULT);
