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authorMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2008-05-12 21:21:10 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-23 22:29:25 +0200
commit5b82a1b08a00b2adca3d9dd9777efff40b7aaaa1 (patch)
tree4dcce4af592ca177bee3dfeb34f9b482d142e713 /kernel/trace/trace_sched_switch.c
parent0aa977f592f17004f9d1d545f2e1bb9ea71896c3 (diff)
Port ftrace to markers
Porting ftrace to the marker infrastructure. Don't need to chain to the wakeup tracer from the sched tracer, because markers support multiple probes connected. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/trace/trace_sched_switch.c')
-rw-r--r--kernel/trace/trace_sched_switch.c171
1 files changed, 143 insertions, 28 deletions
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index a3376478fc2..d25ffa5eaf2 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -16,11 +16,14 @@
static struct trace_array *ctx_trace;
static int __read_mostly tracer_enabled;
+static atomic_t sched_ref;
static void
-ctx_switch_func(void *__rq, struct task_struct *prev, struct task_struct *next)
+sched_switch_func(void *private, void *__rq, struct task_struct *prev,
+ struct task_struct *next)
{
- struct trace_array *tr = ctx_trace;
+ struct trace_array **ptr = private;
+ struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
unsigned long flags;
long disabled;
@@ -41,10 +44,40 @@ ctx_switch_func(void *__rq, struct task_struct *prev, struct task_struct *next)
local_irq_restore(flags);
}
+static notrace void
+sched_switch_callback(void *probe_data, void *call_data,
+ const char *format, va_list *args)
+{
+ struct task_struct *prev;
+ struct task_struct *next;
+ struct rq *__rq;
+
+ if (!atomic_read(&sched_ref))
+ return;
+
+ /* skip prev_pid %d next_pid %d prev_state %ld */
+ (void)va_arg(*args, int);
+ (void)va_arg(*args, int);
+ (void)va_arg(*args, long);
+ __rq = va_arg(*args, typeof(__rq));
+ prev = va_arg(*args, typeof(prev));
+ next = va_arg(*args, typeof(next));
+
+ tracing_record_cmdline(prev);
+
+ /*
+ * If tracer_switch_func only points to the local
+ * switch func, it still needs the ptr passed to it.
+ */
+ sched_switch_func(probe_data, __rq, prev, next);
+}
+
static void
-wakeup_func(void *__rq, struct task_struct *wakee, struct task_struct *curr)
+wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct
+ task_struct *curr)
{
- struct trace_array *tr = ctx_trace;
+ struct trace_array **ptr = private;
+ struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
unsigned long flags;
long disabled;
@@ -67,35 +100,29 @@ wakeup_func(void *__rq, struct task_struct *wakee, struct task_struct *curr)
local_irq_restore(flags);
}
-void
-ftrace_ctx_switch(void *__rq, struct task_struct *prev,
- struct task_struct *next)
+static notrace void
+wake_up_callback(void *probe_data, void *call_data,
+ const char *format, va_list *args)
{
- if (unlikely(atomic_read(&trace_record_cmdline_enabled)))
- tracing_record_cmdline(prev);
+ struct task_struct *curr;
+ struct task_struct *task;
+ struct rq *__rq;
- /*
- * If tracer_switch_func only points to the local
- * switch func, it still needs the ptr passed to it.
- */
- ctx_switch_func(__rq, prev, next);
+ if (likely(!tracer_enabled))
+ return;
- /*
- * Chain to the wakeup tracer (this is a NOP if disabled):
- */
- wakeup_sched_switch(prev, next);
-}
+ /* Skip pid %d state %ld */
+ (void)va_arg(*args, int);
+ (void)va_arg(*args, long);
+ /* now get the meat: "rq %p task %p rq->curr %p" */
+ __rq = va_arg(*args, typeof(__rq));
+ task = va_arg(*args, typeof(task));
+ curr = va_arg(*args, typeof(curr));
-void
-ftrace_wake_up_task(void *__rq, struct task_struct *wakee,
- struct task_struct *curr)
-{
- wakeup_func(__rq, wakee, curr);
+ tracing_record_cmdline(task);
+ tracing_record_cmdline(curr);
- /*
- * Chain to the wakeup tracer (this is a NOP if disabled):
- */
- wakeup_sched_wakeup(wakee, curr);
+ wakeup_func(probe_data, __rq, task, curr);
}
void
@@ -132,15 +159,95 @@ static void sched_switch_reset(struct trace_array *tr)
tracing_reset(tr->data[cpu]);
}
+static int tracing_sched_register(void)
+{
+ int ret;
+
+ ret = marker_probe_register("kernel_sched_wakeup",
+ "pid %d state %ld ## rq %p task %p rq->curr %p",
+ wake_up_callback,
+ &ctx_trace);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't add marker"
+ " probe to kernel_sched_wakeup\n");
+ return ret;
+ }
+
+ ret = marker_probe_register("kernel_sched_wakeup_new",
+ "pid %d state %ld ## rq %p task %p rq->curr %p",
+ wake_up_callback,
+ &ctx_trace);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't add marker"
+ " probe to kernel_sched_wakeup_new\n");
+ goto fail_deprobe;
+ }
+
+ ret = marker_probe_register("kernel_sched_schedule",
+ "prev_pid %d next_pid %d prev_state %ld "
+ "## rq %p prev %p next %p",
+ sched_switch_callback,
+ &ctx_trace);
+ if (ret) {
+ pr_info("sched trace: Couldn't add marker"
+ " probe to kernel_sched_schedule\n");
+ goto fail_deprobe_wake_new;
+ }
+
+ return ret;
+fail_deprobe_wake_new:
+ marker_probe_unregister("kernel_sched_wakeup_new",
+ wake_up_callback,
+ &ctx_trace);
+fail_deprobe:
+ marker_probe_unregister("kernel_sched_wakeup",
+ wake_up_callback,
+ &ctx_trace);
+ return ret;
+}
+
+static void tracing_sched_unregister(void)
+{
+ marker_probe_unregister("kernel_sched_schedule",
+ sched_switch_callback,
+ &ctx_trace);
+ marker_probe_unregister("kernel_sched_wakeup_new",
+ wake_up_callback,
+ &ctx_trace);
+ marker_probe_unregister("kernel_sched_wakeup",
+ wake_up_callback,
+ &ctx_trace);
+}
+
+void tracing_start_sched_switch(void)
+{
+ long ref;
+
+ ref = atomic_inc_return(&sched_ref);
+ if (ref == 1)
+ tracing_sched_register();
+}
+
+void tracing_stop_sched_switch(void)
+{
+ long ref;
+
+ ref = atomic_dec_and_test(&sched_ref);
+ if (ref)
+ tracing_sched_unregister();
+}
+
static void start_sched_trace(struct trace_array *tr)
{
sched_switch_reset(tr);
atomic_inc(&trace_record_cmdline_enabled);
tracer_enabled = 1;
+ tracing_start_sched_switch();
}
static void stop_sched_trace(struct trace_array *tr)
{
+ tracing_stop_sched_switch();
atomic_dec(&trace_record_cmdline_enabled);
tracer_enabled = 0;
}
@@ -181,6 +288,14 @@ static struct tracer sched_switch_trace __read_mostly =
__init static int init_sched_switch_trace(void)
{
+ int ret = 0;
+
+ if (atomic_read(&sched_ref))
+ ret = tracing_sched_register();
+ if (ret) {
+ pr_info("error registering scheduler trace\n");
+ return ret;
+ }
return register_tracer(&sched_switch_trace);
}
device_initcall(init_sched_switch_trace);