[PATCH 2/5] tracing: add previous task state info to sched switch event

From: Steven Rostedt
Date: Wed May 20 2009 - 23:18:43 EST


From: Steven Rostedt <srostedt@xxxxxxxxxx>

It is useful to see the state of a task that is being switched out.
This patch adds the output of the state of the previous task in
the context switch event.

[ Impact: see state of switched out task in context switch ]

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
include/trace/events/sched.h | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index dd4033c..24ab5bc 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -156,6 +156,7 @@ TRACE_EVENT(sched_switch,
__array( char, prev_comm, TASK_COMM_LEN )
__field( pid_t, prev_pid )
__field( int, prev_prio )
+ __field( long, prev_state )
__array( char, next_comm, TASK_COMM_LEN )
__field( pid_t, next_pid )
__field( int, next_prio )
@@ -165,13 +166,19 @@ TRACE_EVENT(sched_switch,
memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
__entry->prev_pid = prev->pid;
__entry->prev_prio = prev->prio;
+ __entry->prev_state = prev->state;
memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
__entry->next_pid = next->pid;
__entry->next_prio = next->prio;
),

- TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
+ TP_printk("task %s:%d [%d] (%s) ==> %s:%d [%d]",
__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
+ __entry->prev_state ?
+ __print_flags(__entry->prev_state, "|",
+ { 1, "S"} , { 2, "D" }, { 4, "T" }, { 8, "t" },
+ { 16, "Z" }, { 32, "X" }, { 64, "x" },
+ { 128, "W" }) : "R",
__entry->next_comm, __entry->next_pid, __entry->next_prio)
);

--
1.6.2.4

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