sched/debug: Provide slice length for fair tasks

Since commit:

  857b158dc5e8 ("sched/eevdf: Use sched_attr::sched_runtime to set request/slice suggestion")

... we have the userspace per-task tunable slice length, which is
a key parameter that is otherwise difficult to obtain, so provide
it in /proc/$PID/sched.

[ mingo: Clarified the changelog. ]

Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/453349b1-1637-42f5-a7b2-2385392b5956@arm.com

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index a1be00a988bf6f15351f6749d9159813c57604a8..5b32d3cc393bfa9d04ff152b56a50d71c48f2145 100644 (file)
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -1265,6 +1265,8 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
        if (task_has_dl_policy(p)) {
                P(dl.runtime);
                P(dl.deadline);
+       } else if (fair_policy(p->policy)) {
+               P(se.slice);
        }
 #ifdef CONFIG_SCHED_CLASS_EXT
        __PS("ext.enabled", task_on_scx(p));