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-rw-r--r--include/linux/tracepoint.h105
-rw-r--r--include/trace/irq_event_types.h8
-rw-r--r--include/trace/sched_event_types.h102
3 files changed, 159 insertions, 56 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 69b56988813d..d35a7ee7611f 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -157,7 +157,110 @@ static inline void tracepoint_synchronize_unregister(void)
#define TRACE_FORMAT(name, proto, args, fmt) \
DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
-#define TRACE_EVENT(name, proto, args, struct, print, assign) \
+
+/*
+ * For use with the TRACE_EVENT macro:
+ *
+ * We define a tracepoint, its arguments, its printk format
+ * and its 'fast binay record' layout.
+ *
+ * Firstly, name your tracepoint via TRACE_EVENT(name : the
+ * 'subsystem_event' notation is fine.
+ *
+ * Think about this whole construct as the
+ * 'trace_sched_switch() function' from now on.
+ *
+ *
+ * TRACE_EVENT(sched_switch,
+ *
+ * *
+ * * A function has a regular function arguments
+ * * prototype, declare it via TP_PROTO():
+ * *
+ *
+ * TP_PROTO(struct rq *rq, struct task_struct *prev,
+ * struct task_struct *next),
+ *
+ * *
+ * * Define the call signature of the 'function'.
+ * * (Design sidenote: we use this instead of a
+ * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
+ * *
+ *
+ * TP_ARGS(rq, prev, next),
+ *
+ * *
+ * * Fast binary tracing: define the trace record via
+ * * TP_STRUCT__entry(). You can think about it like a
+ * * regular C structure local variable definition.
+ * *
+ * * This is how the trace record is structured and will
+ * * be saved into the ring buffer. These are the fields
+ * * that will be exposed to user-space in
+ * * /debug/tracing/events/<*>/format.
+ * *
+ * * The declared 'local variable' is called '__entry'
+ * *
+ * * __field(pid_t, prev_prid) is equivalent to a standard declariton:
+ * *
+ * * pid_t prev_pid;
+ * *
+ * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
+ * *
+ * * char prev_comm[TASK_COMM_LEN];
+ * *
+ *
+ * TP_STRUCT__entry(
+ * __array( char, prev_comm, TASK_COMM_LEN )
+ * __field( pid_t, prev_pid )
+ * __field( int, prev_prio )
+ * __array( char, next_comm, TASK_COMM_LEN )
+ * __field( pid_t, next_pid )
+ * __field( int, next_prio )
+ * ),
+ *
+ * *
+ * * Assign the entry into the trace record, by embedding
+ * * a full C statement block into TP_fast_assign(). You
+ * * can refer to the trace record as '__entry' -
+ * * otherwise you can put arbitrary C code in here.
+ * *
+ * * Note: this C code will execute every time a trace event
+ * * happens, on an active tracepoint.
+ * *
+ *
+ * TP_fast_assign(
+ * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
+ * __entry->prev_pid = prev->pid;
+ * __entry->prev_prio = prev->prio;
+ * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
+ * __entry->next_pid = next->pid;
+ * __entry->next_prio = next->prio;
+ * )
+ *
+ * *
+ * * Formatted output of a trace record via TP_printk().
+ * * This is how the tracepoint will appear under ftrace
+ * * plugins that make use of this tracepoint.
+ * *
+ * * (raw-binary tracing wont actually perform this step.)
+ * *
+ *
+ * TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
+ * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
+ * __entry->next_comm, __entry->next_pid, __entry->next_prio),
+ *
+ * );
+ *
+ * This macro construct is thus used for the regular printk format
+ * tracing setup, it is used to construct a function pointer based
+ * tracepoint callback (this is used by programmatic plugins and
+ * can also by used by generic instrumentation like SystemTap), and
+ * it is also used to expose a structured trace record in
+ * /debug/tracing/events/.
+ */
+
+#define TRACE_EVENT(name, proto, args, struct, assign, print) \
DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#endif
diff --git a/include/trace/irq_event_types.h b/include/trace/irq_event_types.h
index 43bcb74dd49f..214bb928fe9e 100644
--- a/include/trace/irq_event_types.h
+++ b/include/trace/irq_event_types.h
@@ -31,13 +31,13 @@ TRACE_EVENT(irq_handler_exit,
__field( int, ret )
),
- TP_printk("irq=%d return=%s",
- __entry->irq, __entry->ret ? "handled" : "unhandled"),
-
TP_fast_assign(
__entry->irq = irq;
__entry->ret = ret;
- )
+ ),
+
+ TP_printk("irq=%d return=%s",
+ __entry->irq, __entry->ret ? "handled" : "unhandled")
);
#undef TRACE_SYSTEM
diff --git a/include/trace/sched_event_types.h b/include/trace/sched_event_types.h
index fb37af672c88..63547dc1125f 100644
--- a/include/trace/sched_event_types.h
+++ b/include/trace/sched_event_types.h
@@ -22,12 +22,12 @@ TRACE_EVENT(sched_kthread_stop,
__field( pid_t, pid )
),
- TP_printk("task %s:%d", __entry->comm, __entry->pid),
-
TP_fast_assign(
memcpy(__entry->comm, t->comm, TASK_COMM_LEN);
__entry->pid = t->pid;
- )
+ ),
+
+ TP_printk("task %s:%d", __entry->comm, __entry->pid)
);
/*
@@ -43,11 +43,11 @@ TRACE_EVENT(sched_kthread_stop_ret,
__field( int, ret )
),
- TP_printk("ret %d", __entry->ret),
-
TP_fast_assign(
__entry->ret = ret;
- )
+ ),
+
+ TP_printk("ret %d", __entry->ret)
);
/*
@@ -68,14 +68,14 @@ TRACE_EVENT(sched_wait_task,
__field( int, prio )
),
- TP_printk("task %s:%d [%d]",
- __entry->comm, __entry->pid, __entry->prio),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
- )
+ ),
+
+ TP_printk("task %s:%d [%d]",
+ __entry->comm, __entry->pid, __entry->prio)
);
/*
@@ -97,16 +97,16 @@ TRACE_EVENT(sched_wakeup,
__field( int, success )
),
- TP_printk("task %s:%d [%d] success=%d",
- __entry->comm, __entry->pid, __entry->prio,
- __entry->success),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
__entry->success = success;
- )
+ ),
+
+ TP_printk("task %s:%d [%d] success=%d",
+ __entry->comm, __entry->pid, __entry->prio,
+ __entry->success)
);
/*
@@ -128,16 +128,16 @@ TRACE_EVENT(sched_wakeup_new,
__field( int, success )
),
- TP_printk("task %s:%d [%d] success=%d",
- __entry->comm, __entry->pid, __entry->prio,
- __entry->success),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
__entry->success = success;
- )
+ ),
+
+ TP_printk("task %s:%d [%d] success=%d",
+ __entry->comm, __entry->pid, __entry->prio,
+ __entry->success)
);
/*
@@ -162,10 +162,6 @@ TRACE_EVENT(sched_switch,
__field( int, next_prio )
),
- TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
- __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
- __entry->next_comm, __entry->next_pid, __entry->next_prio),
-
TP_fast_assign(
memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
__entry->prev_pid = prev->pid;
@@ -173,7 +169,11 @@ TRACE_EVENT(sched_switch,
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]",
+ __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
+ __entry->next_comm, __entry->next_pid, __entry->next_prio)
);
/*
@@ -193,17 +193,17 @@ TRACE_EVENT(sched_migrate_task,
__field( int, dest_cpu )
),
- TP_printk("task %s:%d [%d] from: %d to: %d",
- __entry->comm, __entry->pid, __entry->prio,
- __entry->orig_cpu, __entry->dest_cpu),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
__entry->orig_cpu = orig_cpu;
__entry->dest_cpu = dest_cpu;
- )
+ ),
+
+ TP_printk("task %s:%d [%d] from: %d to: %d",
+ __entry->comm, __entry->pid, __entry->prio,
+ __entry->orig_cpu, __entry->dest_cpu)
);
/*
@@ -221,14 +221,14 @@ TRACE_EVENT(sched_process_free,
__field( int, prio )
),
- TP_printk("task %s:%d [%d]",
- __entry->comm, __entry->pid, __entry->prio),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
- )
+ ),
+
+ TP_printk("task %s:%d [%d]",
+ __entry->comm, __entry->pid, __entry->prio)
);
/*
@@ -246,14 +246,14 @@ TRACE_EVENT(sched_process_exit,
__field( int, prio )
),
- TP_printk("task %s:%d [%d]",
- __entry->comm, __entry->pid, __entry->prio),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
- )
+ ),
+
+ TP_printk("task %s:%d [%d]",
+ __entry->comm, __entry->pid, __entry->prio)
);
/*
@@ -271,14 +271,14 @@ TRACE_EVENT(sched_process_wait,
__field( int, prio )
),
- TP_printk("task %s:%d [%d]",
- __entry->comm, __entry->pid, __entry->prio),
-
TP_fast_assign(
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
__entry->pid = pid_nr(pid);
__entry->prio = current->prio;
- )
+ ),
+
+ TP_printk("task %s:%d [%d]",
+ __entry->comm, __entry->pid, __entry->prio)
);
/*
@@ -297,16 +297,16 @@ TRACE_EVENT(sched_process_fork,
__field( pid_t, child_pid )
),
- TP_printk("parent %s:%d child %s:%d",
- __entry->parent_comm, __entry->parent_pid,
- __entry->child_comm, __entry->child_pid),
-
TP_fast_assign(
memcpy(__entry->parent_comm, parent->comm, TASK_COMM_LEN);
__entry->parent_pid = parent->pid;
memcpy(__entry->child_comm, child->comm, TASK_COMM_LEN);
__entry->child_pid = child->pid;
- )
+ ),
+
+ TP_printk("parent %s:%d child %s:%d",
+ __entry->parent_comm, __entry->parent_pid,
+ __entry->child_comm, __entry->child_pid)
);
/*
@@ -324,14 +324,14 @@ TRACE_EVENT(sched_signal_send,
__field( pid_t, pid )
),
- TP_printk("sig: %d task %s:%d",
- __entry->sig, __entry->comm, __entry->pid),
-
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->sig = sig;
- )
+ ),
+
+ TP_printk("sig: %d task %s:%d",
+ __entry->sig, __entry->comm, __entry->pid)
);
#undef TRACE_SYSTEM
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-12 14:09:52 +0200