Messages in this thread | | | From | 付元力 Jerry Fu <> | Subject | Re: [PATCH] sched: Introduce task_struct::latency_sensi_flag. | Date | Wed, 8 May 2024 03:02:49 +0000 |
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Sure, my first thought is providing a way to have a low-latency task if user does not want to enable napi threaded. Once it is enabled, which will affect all system. I want to have a low-latency task while minimizing the impact on the system.
Thanks fuyuanli
在 2024/5/6 下午10:04,“Jakub Kicinski”<kuba@kernel.org <mailto:kuba@kernel.org>> 写入:
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.
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