Commit 06eb6184 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched/debug: Add explicit TASK_IDLE printing 



Markus reported that kthreads that idle using TASK_IDLE instead of
TASK_INTERRUPTIBLE are reported in as TASK_UNINTERRUPTIBLE and things
like htop mark those red.

This is undesirable, so add an explicit state for TASK_IDLE.

Reported-by: default avatarMarkus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5f6ad26e

fs/proc/array.c

+13 −8
Original line number Diff line number Diff line
@@ -119,18 +119,23 @@ static inline void task_name(struct seq_file *m, struct task_struct *p) 
 * simple bit tests.

 */

static const char * const task_state_array[] = {

	"R (running)",		/*   0 */

	"S (sleeping)",		/*   1 */

	"D (disk sleep)",	/*   2 */

	"T (stopped)",		/*   4 */

	"t (tracing stop)",	/*   8 */

	"X (dead)",		/*  16 */

	"Z (zombie)",		/*  32 */



	/* states in TASK_REPORT: */

	"R (running)",		/* 0x00 */

	"S (sleeping)",		/* 0x01 */

	"D (disk sleep)",	/* 0x02 */

	"T (stopped)",		/* 0x04 */

	"t (tracing stop)",	/* 0x08 */

	"X (dead)",		/* 0x10 */

	"Z (zombie)",		/* 0x20 */



	/* states beyond TASK_REPORT: */

	"I (idle)",		/* 0x40 */

};



static inline const char *get_task_state(struct task_struct *tsk)

{

	BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array) - 1);

	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array));

	return task_state_array[__get_task_state(tsk)];

}

include/linux/sched.h

+10 −2
Original line number Diff line number Diff line
@@ -1241,22 +1241,30 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk) 
	return task_pgrp_nr_ns(tsk, &init_pid_ns);

}



#define TASK_REPORT_IDLE	(TASK_REPORT + 1)

#define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)



static inline unsigned int __get_task_state(struct task_struct *tsk)

{

	unsigned int tsk_state = READ_ONCE(tsk->state);

	unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;



	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;



	return fls(state);

}



static inline char __task_state_to_char(unsigned int state)

{

	static const char state_char[] = "RSDTtXZ";

	static const char state_char[] = "RSDTtXZI";



	BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != sizeof(state_char) - 2);

	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);



	return state_char[state];

}

include/trace/events/sched.h

+4 −3
Original line number Diff line number Diff line
@@ -156,10 +156,11 @@ TRACE_EVENT(sched_switch, 
	TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d",

		__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,



		(__entry->prev_state & TASK_REPORT) ?

		  __print_flags(__entry->prev_state & TASK_REPORT, "|",

		(__entry->prev_state & (TASK_REPORT_MAX - 1)) ?

		  __print_flags(__entry->prev_state & (TASK_REPORT_MAX - 1), "|",

				{ 0x01, "S" }, { 0x02, "D" }, { 0x04, "T" },

				{ 0x08, "t" }, { 0x10, "X" }, { 0x20, "Z" }) :

				{ 0x08, "t" }, { 0x10, "X" }, { 0x20, "Z" },

				{ 0x40, "I" }) :

		  "R",



		__entry->prev_state & TASK_STATE_MAX ? "+" : "",

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