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>
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 5948011..5d2fb48 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -15,6 +15,7 @@
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
+#include <linux/marker.h>
#include "trace.h"
@@ -44,11 +45,13 @@
return 1;
}
-void
-wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
+static void notrace
+wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
+ struct task_struct *next)
{
unsigned long latency = 0, t0 = 0, t1 = 0;
- struct trace_array *tr = wakeup_trace;
+ struct trace_array **ptr = private;
+ struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
cycle_t T0, T1, delta;
unsigned long flags;
@@ -113,6 +116,31 @@
atomic_dec(&tr->data[cpu]->disabled);
}
+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;
+
+ /* 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.
+ */
+ wakeup_sched_switch(probe_data, __rq, prev, next);
+}
+
static void __wakeup_reset(struct trace_array *tr)
{
struct trace_array_cpu *data;
@@ -188,19 +216,68 @@
atomic_dec(&tr->data[cpu]->disabled);
}
-void wakeup_sched_wakeup(struct task_struct *wakee, struct task_struct *curr)
+static notrace void
+wake_up_callback(void *probe_data, void *call_data,
+ const char *format, va_list *args)
{
+ struct trace_array **ptr = probe_data;
+ struct trace_array *tr = *ptr;
+ struct task_struct *curr;
+ struct task_struct *task;
+ struct rq *__rq;
+
if (likely(!tracer_enabled))
return;
- tracing_record_cmdline(curr);
- tracing_record_cmdline(wakee);
+ /* 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));
- wakeup_check_start(wakeup_trace, wakee, curr);
+ tracing_record_cmdline(task);
+ tracing_record_cmdline(curr);
+
+ wakeup_check_start(tr, task, curr);
}
static void start_wakeup_tracer(struct trace_array *tr)
{
+ int ret;
+
+ ret = marker_probe_register("kernel_sched_wakeup",
+ "pid %d state %ld ## rq %p task %p rq->curr %p",
+ wake_up_callback,
+ &wakeup_trace);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't add marker"
+ " probe to kernel_sched_wakeup\n");
+ return;
+ }
+
+ ret = marker_probe_register("kernel_sched_wakeup_new",
+ "pid %d state %ld ## rq %p task %p rq->curr %p",
+ wake_up_callback,
+ &wakeup_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,
+ &wakeup_trace);
+ if (ret) {
+ pr_info("sched trace: Couldn't add marker"
+ " probe to kernel_sched_schedule\n");
+ goto fail_deprobe_wake_new;
+ }
+
wakeup_reset(tr);
/*
@@ -215,11 +292,28 @@
tracer_enabled = 1;
return;
+fail_deprobe_wake_new:
+ marker_probe_unregister("kernel_sched_wakeup_new",
+ wake_up_callback,
+ &wakeup_trace);
+fail_deprobe:
+ marker_probe_unregister("kernel_sched_wakeup",
+ wake_up_callback,
+ &wakeup_trace);
}
static void stop_wakeup_tracer(struct trace_array *tr)
{
tracer_enabled = 0;
+ marker_probe_unregister("kernel_sched_schedule",
+ sched_switch_callback,
+ &wakeup_trace);
+ marker_probe_unregister("kernel_sched_wakeup_new",
+ wake_up_callback,
+ &wakeup_trace);
+ marker_probe_unregister("kernel_sched_wakeup",
+ wake_up_callback,
+ &wakeup_trace);
}
static void wakeup_tracer_init(struct trace_array *tr)