Re: [RFC PATCH 2/5] sched/events: Introduce cfs_rq load tracking trace event

From: Peter Zijlstra
Date: Tue Mar 28 2017 - 12:58:33 EST


On Tue, Mar 28, 2017 at 06:44:59PM +0200, Peter Zijlstra wrote:
> ---
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -2849,7 +2849,7 @@ static u32 __compute_runnable_contrib(u6
> * = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}]
> */
> static __always_inline int
> -__update_load_avg(u64 now, int cpu, struct sched_avg *sa,
> +___update_load_avg(u64 now, int cpu, struct sched_avg *sa,
> unsigned long weight, int running, struct cfs_rq *cfs_rq)
> {
> u64 delta, scaled_delta, periods;
> @@ -2953,6 +2953,26 @@ __update_load_avg(u64 now, int cpu, stru
> return decayed;
> }
>
> +static int
> +__update_load_avg_blocked_se(u64 now, int cpu, struct sched_avg *sa)
> +{
> + return ___update_load_avg(now, cpu, sa, 0, 0, NULL);
> +}
> +
> +static int
> +__update_load_avg_se(u64 now, int cpu, struct sched_avg *sa,
> + unsigned long weight, int running)
> +{
> + return ___update_load_avg(now, cpu, sa, weight, running, NULL);
> +}
> +
> +static int
> +__update_load_avg(u64 now, int cpu, struct sched_avg *sa,
> + unsigned long weight, int running, struct cfs_rq *cfs_rq)
> +{
> + return ___update_load_avg(now, cpu, sa, weight, running, cfs_rq);

Although ideally we'd be able to tell the compiler that cfs_rq will not
be NULL here. Hurmph.. no __builtin for that I think :/

> +}