diff options
| -rw-r--r-- | kernel/trace/trace.c | 3 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_sysprof.c | 70 |
3 files changed, 73 insertions, 2 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3271916ff033..95b7c48a9a1d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2800,6 +2800,9 @@ static __init void tracer_init_debugfs(void) pr_warning("Could not create debugfs " "'dyn_ftrace_total_info' entry\n"); #endif +#ifdef CONFIG_SYSPROF_TRACER + init_tracer_sysprof_debugfs(d_tracer); +#endif } static int trace_alloc_page(void) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b2198bc830ae..b7f85d9c80d7 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -188,6 +188,8 @@ struct trace_iterator { void tracing_reset(struct trace_array_cpu *data); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *tracing_init_dentry(void); +void init_tracer_sysprof_debugfs(struct dentry *d_tracer); + void ftrace(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index f9a09fe705b0..19406236b67b 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -20,11 +20,12 @@ static struct trace_array *sysprof_trace; static int __read_mostly tracer_enabled; /* - * 10 msecs for now: + * 1 msec sample interval by default: */ -static const unsigned long sample_period = 1000000; +static unsigned long sample_period = 1000000; static const unsigned int sample_max_depth = 512; +static DEFINE_MUTEX(sample_timer_lock); /* * Per CPU hrtimers that do the profiling: */ @@ -166,15 +167,19 @@ static notrace void stack_reset(struct trace_array *tr) static notrace void start_stack_trace(struct trace_array *tr) { + mutex_lock(&sample_timer_lock); stack_reset(tr); start_stack_timers(); tracer_enabled = 1; + mutex_unlock(&sample_timer_lock); } static notrace void stop_stack_trace(struct trace_array *tr) { + mutex_lock(&sample_timer_lock); stop_stack_timers(); tracer_enabled = 0; + mutex_unlock(&sample_timer_lock); } static notrace void stack_trace_init(struct trace_array *tr) @@ -216,3 +221,64 @@ __init static int init_stack_trace(void) return register_tracer(&stack_trace); } device_initcall(init_stack_trace); + +#define MAX_LONG_DIGITS 22 + +static ssize_t +sysprof_sample_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[MAX_LONG_DIGITS]; + int r; + + r = sprintf(buf, "%ld\n", nsecs_to_usecs(sample_period)); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +sysprof_sample_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[MAX_LONG_DIGITS]; + unsigned long val; + + if (cnt > MAX_LONG_DIGITS-1) + cnt = MAX_LONG_DIGITS-1; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + val = simple_strtoul(buf, NULL, 10); + /* + * Enforce a minimum sample period of 100 usecs: + */ + if (val < 100) + val = 100; + + mutex_lock(&sample_timer_lock); + stop_stack_timers(); + sample_period = val * 1000; + start_stack_timers(); + mutex_unlock(&sample_timer_lock); + + return cnt; +} + +static struct file_operations sysprof_sample_fops = { + .read = sysprof_sample_read, + .write = sysprof_sample_write, +}; + +void init_tracer_sysprof_debugfs(struct dentry *d_tracer) +{ + struct dentry *entry; + + entry = debugfs_create_file("sysprof_sample_period", 0644, + d_tracer, NULL, &sysprof_sample_fops); + if (entry) + return; + pr_warning("Could not create debugfs 'dyn_ftrace_total_info' entry\n"); +} |