Commit cb2517653fcc ("sched/debug: Make schedstats a runtime tunable
that is disabled by default") introduced a bug when CONFIG_SCHEDSTATS is
enabled and the runtime tunable is disabled (which is the default). The
wait-time, sum-exec, and sum-sleep fields are missing from the
/proc/sched_debug file in the runnable_tasks section.
Fix it with a new schedstat_val() macro which returns the field value
when schedstats is enabled and zero otherwise. The macro works with
both SCHEDSTATS and !SCHEDSTATS. I put the macro in stats.h since it
might end up being useful in other places.
Fixes: cb2517653fcc ("sched/debug: Make schedstats a runtime tunable that is
disabled by default")
Cc: [email protected]
Signed-off-by: Josh Poimboeuf <[email protected]>
---
kernel/sched/debug.c | 15 ++++-----------
kernel/sched/stats.h | 3 +++
2 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index cf905f6..0368c39 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -427,19 +427,12 @@ print_task(struct seq_file *m, struct rq *rq, struct
task_struct *p)
SPLIT_NS(p->se.vruntime),
(long long)(p->nvcsw + p->nivcsw),
p->prio);
-#ifdef CONFIG_SCHEDSTATS
- if (schedstat_enabled()) {
- SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
- SPLIT_NS(p->se.statistics.wait_sum),
- SPLIT_NS(p->se.sum_exec_runtime),
- SPLIT_NS(p->se.statistics.sum_sleep_runtime));
- }
-#else
+
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
- 0LL, 0L,
+ SPLIT_NS(schedstat_val(p, se.statistics.wait_sum)),
SPLIT_NS(p->se.sum_exec_runtime),
- 0LL, 0L);
-#endif
+ SPLIT_NS(schedstat_val(p, se.statistics.sum_sleep_runtime)));
+
#ifdef CONFIG_NUMA_BALANCING
SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
#endif
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index 70b3b6a..78955cb 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -33,6 +33,8 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long
delta)
# define schedstat_inc(rq, field) do { if (schedstat_enabled()) {
(rq)->field++; } } while (0)
# define schedstat_add(rq, field, amt) do { if (schedstat_enabled()) {
(rq)->field += (amt); } } while (0)
# define schedstat_set(var, val) do { if (schedstat_enabled()) { var =
(val); } } while (0)
+# define schedstat_val(rq, field) ((schedstat_enabled()) ? (rq)->field :
0)
+
#else /* !CONFIG_SCHEDSTATS */
static inline void
rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
@@ -47,6 +49,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
# define schedstat_inc(rq, field) do { } while (0)
# define schedstat_add(rq, field, amt) do { } while (0)
# define schedstat_set(var, val) do { } while (0)
+# define schedstat_val(rq, field) 0
#endif
#ifdef CONFIG_SCHED_INFO
--
2.4.11
