在 2021/2/9 上午12:45, Johannes Weiner 写道: > On Sun, Feb 07, 2021 at 07:56:42PM +0800, Chengming Zhou wrote: >> From: zhouchengming <zhouchengm...@bytedance.com> >> >> When the current task in a cgroup is in_memstall, the corresponding psi_group >> is in PSI_MEM_FULL state > This is correct. > >> so we can remove the redundant psi_task_tick from scheduler_tick to >> save this periodic cost. > But this isn't. It IS the task tick that makes it so. The state change > tracking counts MEMSTALL tasks and ONCPU tasks, but it doesn't check > whether the ONCPU task is the MEMSTALL one.
Yes, you are right, I messed them up... will take a closer look at the code later. Thanks. > It would be possible to incorporate that into psi_task_switch(), but > you have to be careful with the branches because that path is often > hotter than the timer tick. > > This patch by itself breaks page reclaim detection, so NAK.
