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
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -464,33 +464,6 @@
}
-/* "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 @@
/* 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
--- a/drivers/oprofile/cpu_buffer.h
+++ b/drivers/oprofile/cpu_buffer.h
@@ -81,6 +81,33 @@
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
