* Li Yu <raise.sail@xxxxxxxxx> wrote:Thanks, I am wrong at seeing the delta variable is represented by virtual time unit. if the code does as I said, the delta_fair may be too small to meanless.
static void distribute_fair_add(struct rq *rq, s64 delta)
{
struct task_struct *curr = rq->curr;
s64 delta_fair = 0;
if (!(sysctl_sched_load_smoothing & 32))
return;
if (rq->nr_running) {
delta_fair = div64_s(delta, rq->nr_running);
/*
* The currently running task's next wait_runtime value does
* not depend on the fair_clock, so fix it up explicitly:
*/
add_wait_runtime(rq, curr, -delta_fair);
rq->fair_clock -= delta_fair;
}
}
See this line:
delta_fair = div64_s(delta, rq->nr_running);
Ingo, should we be replace "rq->nr_running" with "rq->raw_load_weight" here?
that would break the code. The handling of sleep periods is basically heuristics and using nr_running here appears to be 'good enough' in practice.