On Sat, 11 Jan 2025 at 13:29, Alexandru Lazarev <alexandru.lazarev@xxxxxxxxx> wrote: > In Linux kernel cgroup v2’s CFS scheduler, how is cpu.max throttled_usec accounted when a cgroup with multiple threads gets throttled during a single quota period? Specifically, is throttled_usec tracked as the total wall-clock time that the cgroup was throttled as a whole, or is it a sum of the throttled times of all individual threads? > > Kernel Version: "5.14.0-284.11.1.el9_2.x86_64 #1 SMP PREEMPT_DYNAMIC Tue May 9 11:41:53 PDT 2023 x86_64 x86_64 x86_64 GNU/Linux" Distro: Oracle Linux 9.x Hi When the cgroup is throttled, all tasks (threads) within the cgroup are simultaneously prevented from running. The `throttled_time` counter starts incrementing when the cgroup as a whole enters the throttled state and stops when the cgroup is no longer throttled. Quote: "throttled_time: The total time duration (in nanoseconds) for which entities of the group have been throttled." https://docs.kernel.org/scheduler/sched-bwc.html#:~:text=throttled_time The source: void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) { ... cfs_b->throttled_time += rq_clock(rq) - cfs_rq->throttled_clock; ... static int cpu_extra_stat_show(struct seq_file *sf, struct cgroup_subsys_state *css) { struct task_group *tg = css_tg(css); struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; ... throttled_usec = cfs_b->throttled_time; Costa Thanks _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
