ftrace: sysprof plugin improvement
add sample maximum depth.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index b78f12f..7f6fccc 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -23,6 +23,7 @@
* 10 msecs for now:
*/
static const unsigned long sample_period = 1000000;
+static const unsigned int sample_max_depth = 512;
/*
* Per CPU hrtimers that do the profiling:
@@ -45,8 +46,6 @@
return 1;
}
-#define SYSPROF_MAX_ADDRESSES 512
-
static void timer_notify(struct pt_regs *regs, int cpu)
{
const void __user *frame_pointer;
@@ -80,7 +79,7 @@
frame_pointer = (void __user *)regs->bp;
- for (i = 0; i < SYSPROF_MAX_ADDRESSES; i++) {
+ for (i = 0; i < sample_max_depth; i++) {
if (!copy_stack_frame(frame_pointer, &frame))
break;
if ((unsigned long)frame_pointer < regs->sp)
@@ -93,7 +92,7 @@
trace_special(tr, data, 2, current->pid, i);
- if (i == SYSPROF_MAX_ADDRESSES)
+ if (i == sample_max_depth)
trace_special(tr, data, -1, -1, -1);
}
@@ -126,7 +125,6 @@
for_each_online_cpu(cpu) {
set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
start_stack_timer(cpu);
- printk(KERN_INFO "started sysprof timer on cpu%d\n", cpu);
}
set_cpus_allowed_ptr(current, &saved_mask);
}
@@ -136,7 +134,6 @@
struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);
hrtimer_cancel(hrtimer);
- printk(KERN_INFO "cancelled sysprof timer on cpu%d\n", cpu);
}
static void stop_stack_timers(void)