Hi Costa, Thx U very much for your response. On Sat, Jan 11, 2025 at 7:03 PM Costa Shulyupin <costa.shul@xxxxxxxxxx> wrote: > <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 > Wanted experts' confirmations :), because IMHO I got confused by this "The total time duration (in nanoseconds) for which entities". Someone (those 'smart' AI chats) interpreted them as cumulative time of all throttled threads/processes within a cgroup, and also due to missing description of "throttled_usec" in cgroup v2 in https://docs.kernel.org/admin-guide/cgroup-v2.html#cgroup-v2-cpu:~:text=nr_throttled-,throttled_usec,-nr_bursts > 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 > Regards, AlexL _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
