#include <linux/debugfs.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
-#include <linux/marker.h>
#include <linux/ftrace.h>
+#include <trace/sched.h>
#include "trace.h"
static struct trace_array *ctx_trace;
static int __read_mostly tracer_enabled;
-static atomic_t sched_ref;
+static int sched_ref;
+static DEFINE_MUTEX(sched_register_mutex);
static void
-sched_switch_func(void *private, void *__rq, struct task_struct *prev,
+probe_sched_switch(struct rq *__rq, struct task_struct *prev,
struct task_struct *next)
{
- struct trace_array **ptr = private;
- struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
unsigned long flags;
- long disabled;
int cpu;
+ int pc;
+
+ if (!sched_ref)
+ return;
tracing_record_cmdline(prev);
tracing_record_cmdline(next);
if (!tracer_enabled)
return;
+ pc = preempt_count();
local_irq_save(flags);
cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
+ data = ctx_trace->data[cpu];
- if (likely(disabled == 1))
- tracing_sched_switch_trace(tr, data, prev, next, flags);
+ if (likely(!atomic_read(&data->disabled)))
+ tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc);
- atomic_dec(&data->disabled);
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));
-
- /*
- * 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 *private, void *__rq, struct task_struct *wakee, struct
- task_struct *curr)
+probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
{
- struct trace_array **ptr = private;
- struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
unsigned long flags;
- long disabled;
- int cpu;
+ int cpu, pc;
- if (!tracer_enabled)
+ if (!likely(tracer_enabled))
return;
- tracing_record_cmdline(curr);
+ pc = preempt_count();
+ tracing_record_cmdline(current);
local_irq_save(flags);
cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
+ data = ctx_trace->data[cpu];
- if (likely(disabled == 1))
- tracing_sched_wakeup_trace(tr, data, wakee, curr, flags);
+ if (likely(!atomic_read(&data->disabled)))
+ tracing_sched_wakeup_trace(ctx_trace, data, wakee, current,
+ flags, pc);
- atomic_dec(&data->disabled);
local_irq_restore(flags);
}
-static notrace void
-wake_up_callback(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- struct task_struct *curr;
- struct task_struct *task;
- struct rq *__rq;
-
- if (likely(!tracer_enabled))
- return;
-
- /* 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));
-
- tracing_record_cmdline(task);
- tracing_record_cmdline(curr);
-
- wakeup_func(probe_data, __rq, task, curr);
-}
-
-static void sched_switch_reset(struct trace_array *tr)
-{
- int cpu;
-
- tr->time_start = ftrace_now(tr->cpu);
-
- for_each_online_cpu(cpu)
- 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);
+ ret = register_trace_sched_wakeup(probe_sched_wakeup);
if (ret) {
- pr_info("wakeup trace: Couldn't add marker"
+ pr_info("wakeup trace: Couldn't activate tracepoint"
" 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);
+ ret = register_trace_sched_wakeup_new(probe_sched_wakeup);
if (ret) {
- pr_info("wakeup trace: Couldn't add marker"
+ pr_info("wakeup trace: Couldn't activate tracepoint"
" 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);
+ ret = register_trace_sched_switch(probe_sched_switch);
if (ret) {
- pr_info("sched trace: Couldn't add marker"
+ pr_info("sched trace: Couldn't activate tracepoint"
" 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);
+ unregister_trace_sched_wakeup_new(probe_sched_wakeup);
fail_deprobe:
- marker_probe_unregister("kernel_sched_wakeup",
- wake_up_callback,
- &ctx_trace);
+ unregister_trace_sched_wakeup(probe_sched_wakeup);
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);
+ unregister_trace_sched_switch(probe_sched_switch);
+ unregister_trace_sched_wakeup_new(probe_sched_wakeup);
+ unregister_trace_sched_wakeup(probe_sched_wakeup);
}
static void tracing_start_sched_switch(void)
{
- long ref;
-
- ref = atomic_inc_return(&sched_ref);
- if (ref == 1)
+ mutex_lock(&sched_register_mutex);
+ if (!(sched_ref++))
tracing_sched_register();
+ mutex_unlock(&sched_register_mutex);
}
static void tracing_stop_sched_switch(void)
{
- long ref;
-
- ref = atomic_dec_and_test(&sched_ref);
- if (ref)
+ mutex_lock(&sched_register_mutex);
+ if (!(--sched_ref))
tracing_sched_unregister();
+ mutex_unlock(&sched_register_mutex);
}
void tracing_start_cmdline_record(void)
tracing_stop_sched_switch();
}
+/**
+ * tracing_start_sched_switch_record - start tracing context switches
+ *
+ * Turns on context switch tracing for a tracer.
+ */
+void tracing_start_sched_switch_record(void)
+{
+ if (unlikely(!ctx_trace)) {
+ WARN_ON(1);
+ return;
+ }
+
+ tracing_start_sched_switch();
+
+ mutex_lock(&sched_register_mutex);
+ tracer_enabled++;
+ mutex_unlock(&sched_register_mutex);
+}
+
+/**
+ * tracing_stop_sched_switch_record - start tracing context switches
+ *
+ * Turns off context switch tracing for a tracer.
+ */
+void tracing_stop_sched_switch_record(void)
+{
+ mutex_lock(&sched_register_mutex);
+ tracer_enabled--;
+ WARN_ON(tracer_enabled < 0);
+ mutex_unlock(&sched_register_mutex);
+
+ tracing_stop_sched_switch();
+}
+
+/**
+ * tracing_sched_switch_assign_trace - assign a trace array for ctx switch
+ * @tr: trace array pointer to assign
+ *
+ * Some tracers might want to record the context switches in their
+ * trace. This function lets those tracers assign the trace array
+ * to use.
+ */
+void tracing_sched_switch_assign_trace(struct trace_array *tr)
+{
+ ctx_trace = tr;
+}
+
static void start_sched_trace(struct trace_array *tr)
{
- sched_switch_reset(tr);
- tracing_start_cmdline_record();
- tracer_enabled = 1;
+ tracing_reset_online_cpus(tr);
+ tracing_start_sched_switch_record();
}
static void stop_sched_trace(struct trace_array *tr)
{
- tracer_enabled = 0;
- tracing_stop_cmdline_record();
+ tracing_stop_sched_switch_record();
}
-static void sched_switch_trace_init(struct trace_array *tr)
+static int sched_switch_trace_init(struct trace_array *tr)
{
ctx_trace = tr;
-
- if (tr->ctrl)
- start_sched_trace(tr);
+ start_sched_trace(tr);
+ return 0;
}
static void sched_switch_trace_reset(struct trace_array *tr)
{
- if (tr->ctrl)
+ if (sched_ref)
stop_sched_trace(tr);
}
-static void sched_switch_trace_ctrl_update(struct trace_array *tr)
+static void sched_switch_trace_start(struct trace_array *tr)
{
- /* When starting a new trace, reset the buffers */
- if (tr->ctrl)
- start_sched_trace(tr);
- else
- stop_sched_trace(tr);
+ tracing_reset_online_cpus(tr);
+ tracing_start_sched_switch();
+}
+
+static void sched_switch_trace_stop(struct trace_array *tr)
+{
+ tracing_stop_sched_switch();
}
static struct tracer sched_switch_trace __read_mostly =
.name = "sched_switch",
.init = sched_switch_trace_init,
.reset = sched_switch_trace_reset,
- .ctrl_update = sched_switch_trace_ctrl_update,
+ .start = sched_switch_trace_start,
+ .stop = sched_switch_trace_stop,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_sched_switch,
#endif
__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);
+
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff