Messages in this thread Patch in this message | | | From | Valentin Schneider <> | Subject | [PATCH v2 2/2] sched/tracing: Add TASK_RTLOCK_WAIT to TASK_REPORT | Date | Mon, 17 Jan 2022 16:46:33 +0000 |
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TASK_RTLOCK_WAIT currently isn't part of TASK_REPORT, thus a task blocking on an rtlock will appear as having a task state == 0, IOW TASK_RUNNING.
The actual state is saved in p->saved_state, but reading it after reading p->__state has a few issues: o that could still be TASK_RUNNING in the case of e.g. rt_spin_lock o ttwu_state_match() might have changed that to TASK_RUNNING
Add TASK_RTLOCK_WAIT to TASK_REPORT.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- fs/proc/array.c | 3 ++- include/linux/sched.h | 17 +++++++++-------- include/trace/events/sched.h | 1 + 3 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/fs/proc/array.c b/fs/proc/array.c index ff869a66b34e..f4cae65529a6 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -128,9 +128,10 @@ static const char * const task_state_array[] = { "X (dead)", /* 0x10 */ "Z (zombie)", /* 0x20 */ "P (parked)", /* 0x40 */ + "L (rt-locked)", /* 0x80 */ /* states beyond TASK_REPORT: */ - "I (idle)", /* 0x80 */ + "I (idle)", /* 0x100 */ }; static inline const char *get_task_state(struct task_struct *tsk) diff --git a/include/linux/sched.h b/include/linux/sched.h index d00837d12b9d..18fd77578dae 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -91,13 +91,14 @@ struct task_group; #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) /* Used in tsk->state again: */ #define TASK_PARKED 0x0040 -#define TASK_DEAD 0x0080 -#define TASK_WAKEKILL 0x0100 -#define TASK_WAKING 0x0200 -#define TASK_NOLOAD 0x0400 -#define TASK_NEW 0x0800 /* RT specific auxilliary flag to mark RT lock waiters */ -#define TASK_RTLOCK_WAIT 0x1000 +#define TASK_RTLOCK_WAIT 0x0080 + +#define TASK_DEAD 0x0100 +#define TASK_WAKEKILL 0x0200 +#define TASK_WAKING 0x0400 +#define TASK_NOLOAD 0x0800 +#define TASK_NEW 0x1000 #define TASK_STATE_MAX 0x2000 /* Convenience macros for the sake of set_current_state: */ @@ -114,7 +115,7 @@ struct task_group; #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ - TASK_PARKED) + TASK_PARKED | TASK_RTLOCK_WAIT) #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) @@ -1636,7 +1637,7 @@ static inline unsigned int task_state_index(struct task_struct *tsk) static inline char task_index_to_char(unsigned int state) { - static const char state_char[] = "RSDTtXZPI"; + static const char state_char[] = "RSDTtXZPLI"; BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 65e786756321..f86ec9af19ff 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -261,6 +261,7 @@ TRACE_EVENT(sched_switch, { EXIT_DEAD, "X" }, { EXIT_ZOMBIE, "Z" }, { TASK_PARKED, "P" }, + { TASK_RTLOCK_WAIT, "L" }, { TASK_DEAD, "I" }) : "R", -- 2.25.1
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