tracing: add hierarchical enabling of events

[safe/jmp/linux-2.6] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0aeb3b9..dd40d23 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -639,6 +639,16 @@ void tracing_reset_online_cpus(struct trace_array *tr)
                tracing_reset(tr, cpu);
 }
 
+void tracing_reset_current(int cpu)
+{
+       tracing_reset(&global_trace, cpu);
+}
+
+void tracing_reset_current_online_cpus(void)
+{
+       tracing_reset_online_cpus(&global_trace);
+}
+
 #define SAVED_CMDLINES 128
 #define NO_CMDLINE_MAP UINT_MAX
 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
@@ -887,21 +897,21 @@ trace_current_buffer_lock_reserve(int type, unsigned long len,
        return trace_buffer_lock_reserve(&global_trace,
                                         type, len, flags, pc);
 }
-EXPORT_SYMBOL(trace_current_buffer_lock_reserve);
+EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve);
 
 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
                                        unsigned long flags, int pc)
 {
        __trace_buffer_unlock_commit(&global_trace, event, flags, pc, 1);
 }
-EXPORT_SYMBOL(trace_current_buffer_unlock_commit);
+EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit);
 
 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
                                        unsigned long flags, int pc)
 {
        __trace_buffer_unlock_commit(&global_trace, event, flags, pc, 0);
 }
-EXPORT_SYMBOL(trace_nowake_buffer_unlock_commit);
+EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit);
 
 void trace_current_buffer_discard_commit(struct ring_buffer_event *event)
 {
@@ -3542,7 +3552,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
                }
 
                r = ring_buffer_read_page(ref->buffer, &ref->page,
-                                         len, info->cpu, 0);
+                                         len, info->cpu, 1);
                if (r < 0) {
                        ring_buffer_free_read_page(ref->buffer,
                                                   ref->page);
@@ -3595,6 +3605,45 @@ static const struct file_operations tracing_buffers_fops = {
        .llseek         = no_llseek,
 };
 
+static ssize_t
+tracing_stats_read(struct file *filp, char __user *ubuf,
+                  size_t count, loff_t *ppos)
+{
+       unsigned long cpu = (unsigned long)filp->private_data;
+       struct trace_array *tr = &global_trace;
+       struct trace_seq *s;
+       unsigned long cnt;
+
+       s = kmalloc(sizeof(*s), GFP_ATOMIC);
+       if (!s)
+               return ENOMEM;
+
+       trace_seq_init(s);
+
+       cnt = ring_buffer_entries_cpu(tr->buffer, cpu);
+       trace_seq_printf(s, "entries: %ld\n", cnt);
+
+       cnt = ring_buffer_overrun_cpu(tr->buffer, cpu);
+       trace_seq_printf(s, "overrun: %ld\n", cnt);
+
+       cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu);
+       trace_seq_printf(s, "commit overrun: %ld\n", cnt);
+
+       cnt = ring_buffer_nmi_dropped_cpu(tr->buffer, cpu);
+       trace_seq_printf(s, "nmi dropped: %ld\n", cnt);
+
+       count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
+
+       kfree(s);
+
+       return count;
+}
+
+static const struct file_operations tracing_stats_fops = {
+       .open           = tracing_open_generic,
+       .read           = tracing_stats_read,
+};
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 int __weak ftrace_arch_read_dyn_info(char *buf, int size)
@@ -3708,6 +3757,9 @@ static void tracing_init_debugfs_percpu(long cpu)
 
        trace_create_file("trace_pipe_raw", 0444, d_cpu,
                        (void *) cpu, &tracing_buffers_fops);
+
+       trace_create_file("stats", 0444, d_cpu,
+                       (void *) cpu, &tracing_stats_fops);
 }
 
 #ifdef CONFIG_FTRACE_SELFTEST