This patch allows for reading the current (leftover) runtime and
absolute deadline of a SCHED_DEADLINE task through /proc/*/sched
(entries dl.runtime and dl.deadline), while debugging/testing.
Signed-off-by: Tommaso Cucinotta <tommaso.cucino...@sssup.it>
Reviewed-by: Juri Lelli <juri.le...@arm.com>
Reviewed-by: Luca Abeni <luca.ab...@unitn.it>
Acked-by: Daniel Bistrot de Oliveira <danielbris...@gmail.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Ingo Molnar <mi...@kernel.org>
---
Documentation/scheduler/sched-deadline.txt | 6 ++++++
kernel/sched/debug.c | 4 ++++
2 files changed, 10 insertions(+)
diff --git a/Documentation/scheduler/sched-deadline.txt
b/Documentation/scheduler/sched-deadline.txt
index 8e37b0b..cbc1b46 100644
--- a/Documentation/scheduler/sched-deadline.txt
+++ b/Documentation/scheduler/sched-deadline.txt
@@ -408,6 +408,11 @@ CONTENTS
* the new scheduling related syscalls that manipulate it, i.e.,
sched_setattr() and sched_getattr() are implemented.
+ For debugging purposes, the leftover runtime and absolute deadline of a
+ SCHED_DEADLINE task can be retrieved through /proc/<pid>/sched (entries
+ dl.runtime and dl.deadline, both values in ns). A programmatic way to
+ retrieve these values from production code is under discussion.
+
4.3 Default behavior
---------------------
@@ -476,6 +481,7 @@ CONTENTS
Still missing:
+ - programmatic way to retrieve current runtime and absolute deadline
- refinements to deadline inheritance, especially regarding the possibility
of retaining bandwidth isolation among non-interacting tasks. This is
being studied from both theoretical and practical points of view, and
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index fa178b6..109adc0 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -953,6 +953,10 @@ void proc_sched_show_task(struct task_struct *p, struct
seq_file *m)
#endif
P(policy);
P(prio);
+ if (p->policy == SCHED_DEADLINE) {
+ P(dl.runtime);
+ P(dl.deadline);
+ }
#undef PN_SCHEDSTAT
#undef PN
#undef __PN
--
2.7.4
