Re: [PATCH] tg: add cpu's wait_count of a task group

Tejun Heo
2021-01-15T20:19:15Z

Hello,

On Fri, Jan 15, 2021 at 10:30:05PM +0800, wu860403-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
> - seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time);
...
> + seq_printf(sf, "nr_periods %d\n"
> + "nr_throttled %d\n"
> + "throttled_usec %llu\n",
> + cfs_b->nr_periods, cfs_b->nr_throttled,
> + throttled_usec);

This is interface breaking change. I don't think we can do this at this
point.

> @@ -8255,6 +8265,19 @@ static int cpu_extra_stat_show(struct seq_file *sf,
> "throttled_usec %llu\n",
> cfs_b->nr_periods, cfs_b->nr_throttled,
> throttled_usec);
> + 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?

Thanks.

--
tejun