sched/debug: Add explicit TASK_PARKED printing

Currently TASK_PARKED is masqueraded as TASK_INTERRUPTIBLE, give it
its own print state because it will not in fact get woken by regular
wakeups and is a long-term state.

This requires moving TASK_PARKED into the TASK_REPORT mask, and since
that latter needs to be a contiguous bitmask, we need to shuffle the
bits around a bit.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: Peter Zijlstra

fs/proc/array.c

@@ -128,9 +128,10 @@ static const char * const task_state_array[] = {
 	"t (tracing stop)",	/* 0x08 */
 	"X (dead)",		/* 0x10 */
 	"Z (zombie)",		/* 0x20 */
+	"P (parked)",		/* 0x40 */
 
 	/* states beyond TASK_REPORT: */
-	"I (idle)",		/* 0x40 */
+	"I (idle)",		/* 0x80 */
 };
 
 static inline const char *get_task_state(struct task_struct *tsk)

include/linux/sched.h

@@ -75,10 +75,10 @@ struct task_group;
 #define EXIT_ZOMBIE			0x0020
 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
 /* Used in tsk->state again: */
-#define TASK_DEAD			0x0040
-#define TASK_WAKEKILL			0x0080
-#define TASK_WAKING			0x0100
-#define TASK_PARKED			0x0200
+#define TASK_PARKED			0x0040
+#define TASK_DEAD			0x0080
+#define TASK_WAKEKILL			0x0100
+#define TASK_WAKING			0x0200
 #define TASK_NOLOAD			0x0400
 #define TASK_NEW			0x0800
 #define TASK_STATE_MAX			0x1000
@@ -97,7 +97,8 @@ struct task_group;
 /* get_task_state(): */
 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
-					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE)
+					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
+					 TASK_PARKED)
 
 #define task_is_traced(task)		((task->state & __TASK_TRACED) != 0)
 
@@ -1251,9 +1252,6 @@ static inline unsigned int __get_task_state(struct task_struct *tsk)
 
 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
 
-	if (tsk_state == TASK_PARKED)
-		state = TASK_INTERRUPTIBLE;
-
 	if (tsk_state == TASK_IDLE)
 		state = TASK_REPORT_IDLE;
 
@@ -1262,7 +1260,7 @@ static inline unsigned int __get_task_state(struct task_struct *tsk)
 
 static inline char __task_state_to_char(unsigned int state)
 {
-	static const char state_char[] = "RSDTtXZI";
+	static const char state_char[] = "RSDTtXZPI";
 
 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
 

include/trace/events/sched.h

@@ -160,7 +160,7 @@ TRACE_EVENT(sched_switch,
 		  __print_flags(__entry->prev_state & (TASK_REPORT_MAX - 1), "|",
 				{ 0x01, "S" }, { 0x02, "D" }, { 0x04, "T" },
 				{ 0x08, "t" }, { 0x10, "X" }, { 0x20, "Z" },
-				{ 0x40, "I" }) :
+				{ 0x40, "P" }, { 0x80, "I" }) :
 		  "R",
 
 		__entry->prev_state & TASK_STATE_MAX ? "+" : "",