oprofile: adding cpu_buffer_entries()

This is in preparation for changes in the cpu buffer implementation.

Signed-off-by: Robert Richter <robert.richter@amd.com>

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index 44f676c..aed286c 100644 (file)
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -464,33 +464,6 @@ static inline int is_code(unsigned long val)
 }
 
 
-/* "acquire" as many cpu buffer slots as we can */
-static unsigned long get_slots(struct oprofile_cpu_buffer *b)
-{
-       unsigned long head = b->head_pos;
-       unsigned long tail = b->tail_pos;
-
-       /*
-        * Subtle. This resets the persistent last_task
-        * and in_kernel values used for switching notes.
-        * BUT, there is a small window between reading
-        * head_pos, and this call, that means samples
-        * can appear at the new head position, but not
-        * be prefixed with the notes for switching
-        * kernel mode or a task switch. This small hole
-        * can lead to mis-attribution or samples where
-        * we don't know if it's in the kernel or not,
-        * at the start of an event buffer.
-        */
-       cpu_buffer_reset(b);
-
-       if (head >= tail)
-               return head - tail;
-
-       return head + (b->buffer_size - tail);
-}
-
-
 /* Move tasks along towards death. Any tasks on dead_tasks
  * will definitely have no remaining references in any
  * CPU buffers at this point, because we use two lists,
@@ -576,11 +549,11 @@ void sync_buffer(int cpu)
        /* Remember, only we can modify tail_pos */
 
 #ifndef CONFIG_OPROFILE_IBS
-       available = get_slots(cpu_buf);
+       available = cpu_buffer_entries(cpu_buf);
 
        for (i = 0; i < available; ++i) {
 #else
-       while (get_slots(cpu_buf)) {
+       while (cpu_buffer_entries(cpu_buf)) {
 #endif
                struct op_sample *s = cpu_buffer_read_entry(cpu_buf);
 

diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h
index e608976..6055b56 100644 (file)
--- a/drivers/oprofile/cpu_buffer.h
+++ b/drivers/oprofile/cpu_buffer.h
@@ -81,6 +81,33 @@ struct op_sample *cpu_buffer_read_entry(struct oprofile_cpu_buffer *cpu_buf)
        return &cpu_buf->buffer[cpu_buf->tail_pos];
 }
 
+/* "acquire" as many cpu buffer slots as we can */
+static inline
+unsigned long cpu_buffer_entries(struct oprofile_cpu_buffer *b)
+{
+       unsigned long head = b->head_pos;
+       unsigned long tail = b->tail_pos;
+
+       /*
+        * Subtle. This resets the persistent last_task
+        * and in_kernel values used for switching notes.
+        * BUT, there is a small window between reading
+        * head_pos, and this call, that means samples
+        * can appear at the new head position, but not
+        * be prefixed with the notes for switching
+        * kernel mode or a task switch. This small hole
+        * can lead to mis-attribution or samples where
+        * we don't know if it's in the kernel or not,
+        * at the start of an event buffer.
+        */
+       cpu_buffer_reset(b);
+
+       if (head >= tail)
+               return head - tail;
+
+       return head + (b->buffer_size - tail);
+}
+
 /* transient events for the CPU buffer -> event buffer */
 #define CPU_IS_KERNEL 1
 #define CPU_TRACE_BEGIN 2