[PATCH] sched/tracing: correct the task blocking state

[alexs@kernel.org]

From: Alex Shi <alexs@kernel.org>

commit 80ed87c8a9ca ("sched/wait: Introduce TASK_NOLOAD and TASK_IDLE")
stopped the idle kthreads contribution to loadavg. Also task idle should
separated from blocked state too, otherwise we will get incorrect task
blocking state from event tracing sched:sched_stat_blocked.

Originally-from: Curu Wong <curuwang@tencent.com>
Signed-off-by: Alex Shi <alexs@kernel.org>
To: linux-kernel@vger.kernel.org
To: Valentin Schneider <vschneid@redhat.com>
To: Daniel Bristot de Oliveira <bristot@redhat.com>
To: Mel Gorman <mgorman@suse.de>
To: Ben Segall <bsegall@google.com>
To: Steven Rostedt <rostedt@goodmis.org>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
To: Juri Lelli <juri.lelli@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@redhat.com>
---
 include/linux/sched.h   | 4 ++++
 kernel/sched/deadline.c | 2 +-
 kernel/sched/fair.c     | 2 +-
 kernel/sched/rt.c       | 2 +-
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 292c31697248..341e62255ea7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -140,6 +140,10 @@ struct user_event_mm;
 #define is_special_task_state(state)				\
 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
 
+/* blocked task is UNINTERRUPTIBLE but not NOLOAD */
+#define is_blocked_task_state(state)				\
+	((state) & TASK_UNINTERRUPTIBLE && (!((state) & TASK_NOLOAD)))
+
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 # define debug_normal_state_change(state_value)				\
 	do {								\
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index b28114478b82..b6afa596f071 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1570,7 +1570,7 @@ update_stats_dequeue_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se,
 			__schedstat_set(p->stats.sleep_start,
 					rq_clock(rq_of_dl_rq(dl_rq)));
 
-		if (state & TASK_UNINTERRUPTIBLE)
+		if (is_blocked_task_state(state))
 			__schedstat_set(p->stats.block_start,
 					rq_clock(rq_of_dl_rq(dl_rq)));
 	}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d7a3c63a2171..349b0c5104b6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1281,7 +1281,7 @@ update_stats_dequeue_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, int fl
 		if (state & TASK_INTERRUPTIBLE)
 			__schedstat_set(tsk->stats.sleep_start,
 				      rq_clock(rq_of(cfs_rq)));
-		if (state & TASK_UNINTERRUPTIBLE)
+		if (is_blocked_task_state(state))
 			__schedstat_set(tsk->stats.block_start,
 				      rq_clock(rq_of(cfs_rq)));
 	}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 6aaf0a3d6081..2fdf3d71428d 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1375,7 +1375,7 @@ update_stats_dequeue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se,
 			__schedstat_set(p->stats.sleep_start,
 					rq_clock(rq_of_rt_rq(rt_rq)));
 
-		if (state & TASK_UNINTERRUPTIBLE)
+		if (is_blocked_task_state(state))
 			__schedstat_set(p->stats.block_start,
 					rq_clock(rq_of_rt_rq(rt_rq)));
 	}
-- 
2.43.0