Hello, On Mon, Jan 18, 2021 at 11:07:47AM +0800, liming wu wrote: > > > + if (schedstat_enabled() && tg != &root_task_group) { > > > + u64 ws = 0; > > > + u64 wc = 0; > > > + int i; > > > + > > > + for_each_possible_cpu(i) { > > > + ws += schedstat_val(tg->se[i]->statistics.wait_sum); > > > + wc += schedstat_val(tg->se[i]->statistics.wait_count); > > > + } > > > + > > > + seq_printf(sf, "wait_sum %llu\n" > > > + "wait_count %llu\n", ws, wc); > > > + } > > > > What does sum/count tell? > It can tell the task group average latency of every context switch > wait_sum is equivalent to sched_info->run_delay (the second parameter > of /proc/$pid/schedstat) > wait_count is equivalent to sched_info->pcount(the third parameter of > /proc/$pid/schedstat) Sounds good to me but can you please: * Rename wait_sum to wait_usec and make sure the duration is in usecs. * Rename wait_count to nr_waits. * This should go through the scheduler tree. When you post the updated version, please cc the scheduler folks from MAINAINERS. Thanks. -- tejun