Re: [PATCH] sched: Introduce task_struct::latency_sensi_flag.

[Jakub Kicinski]

On Sun, 5 May 2024 11:06:15 +0800 fuyuanli wrote:
> A test has been made in two hosts named A and B. In A, several clients
> sent udp packets to a single server in B concurrently as fast as
> possible. In B, the IRQs of these flows were bound to CPU 0 by flow
> director, so there was always a triggered net_rx softirq on CPU 0. Then
> a test program was started in B, which was also bound to CPU 0, and
> keeped calling sendto() in a loop. Sampling with perf, results showed
> that about 25% of running time of test program was spent executing
> local_bh_enable() contained in syscall sendto(), but after setting
> latency_sensi_flag to 1, this proportion had been reduced to 0.5%.

Enable threaded NAPI, it will have the same effect.