tracing: Have trace_array keep track if snapshot buffer is allocated

[firefly-linux-kernel-4.4.55.git] / kernel / trace / trace.h

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 6728a249e8174874f51cc4f879045c4fedbe4899..1a456c291a07413a81df9796f4b0fcbbd76d42fe 100644 (file)
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -167,16 +167,38 @@ struct trace_array_cpu {
 
 struct tracer;
 
+struct trace_buffer {
+       struct trace_array              *tr;
+       struct ring_buffer              *buffer;
+       struct trace_array_cpu __percpu *data;
+       cycle_t                         time_start;
+       int                             cpu;
+};
+
 /*
  * The trace array - an array of per-CPU trace arrays. This is the
  * highest level data structure that individual tracers deal with.
  * They have on/off state as well:
  */
 struct trace_array {
-       struct ring_buffer      *buffer;
        struct list_head        list;
        char                    *name;
-       int                     cpu;
+       struct trace_buffer     trace_buffer;
+#ifdef CONFIG_TRACER_MAX_TRACE
+       /*
+        * The max_buffer is used to snapshot the trace when a maximum
+        * latency is reached, or when the user initiates a snapshot.
+        * Some tracers will use this to store a maximum trace while
+        * it continues examining live traces.
+        *
+        * The buffers for the max_buffer are set up the same as the trace_buffer
+        * When a snapshot is taken, the buffer of the max_buffer is swapped
+        * with the buffer of the trace_buffer and the buffers are reset for
+        * the trace_buffer so the tracing can continue.
+        */
+       struct trace_buffer     max_buffer;
+       bool                    allocated_snapshot;
+#endif
        int                     buffer_disabled;
        struct trace_cpu        trace_cpu;      /* place holder */
 #ifdef CONFIG_FTRACE_SYSCALLS
@@ -189,7 +211,6 @@ struct trace_array {
        int                     clock_id;
        struct tracer           *current_trace;
        unsigned int            flags;
-       cycle_t                 time_start;
        raw_spinlock_t          start_lock;
        struct dentry           *dir;
        struct dentry           *options;
@@ -198,7 +219,6 @@ struct trace_array {
        struct list_head        systems;
        struct list_head        events;
        struct task_struct      *waiter;
-       struct trace_array_cpu __percpu *data;
 };
 
 enum {
@@ -345,9 +365,10 @@ struct tracer {
        struct tracer           *next;
        struct tracer_flags     *flags;
        bool                    print_max;
-       bool                    use_max_tr;
-       bool                    allocated_snapshot;
        bool                    enabled;
+#ifdef CONFIG_TRACER_MAX_TRACE
+       bool                    use_max_tr;
+#endif
 };
 
 
@@ -493,10 +514,10 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
-void tracing_reset(struct trace_array *tr, int cpu);
-void tracing_reset_online_cpus(struct trace_array *tr);
+void tracing_reset(struct trace_buffer *buf, int cpu);
+void tracing_reset_online_cpus(struct trace_buffer *buf);
 void tracing_reset_current(int cpu);
-void tracing_reset_current_online_cpus(void);
+void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 struct dentry *trace_create_file(const char *name,
                                 umode_t mode,
@@ -674,6 +695,8 @@ trace_array_vprintk(struct trace_array *tr,
                    unsigned long ip, const char *fmt, va_list args);
 int trace_array_printk(struct trace_array *tr,
                       unsigned long ip, const char *fmt, ...);
+int trace_array_printk_buf(struct ring_buffer *buffer,
+                          unsigned long ip, const char *fmt, ...);
 void trace_printk_seq(struct trace_seq *s);
 enum print_line_t print_trace_line(struct trace_iterator *iter);