Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux...

[~andy/linux] / tools / perf / perf.h

diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 95aaf565c704fb6ea67cee78d49e177f0ba8f595..a5fc660c1f1286512b299342ad3841509a080194 100644 (file)
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -94,6 +94,32 @@ void get_term_dimensions(struct winsize *ws);
 #include "util/types.h"
 #include <stdbool.h>
 
+struct perf_mmap {
+       void                    *base;
+       int                     mask;
+       unsigned int            prev;
+};
+
+static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm)
+{
+       struct perf_event_mmap_page *pc = mm->base;
+       int head = pc->data_head;
+       rmb();
+       return head;
+}
+
+static inline void perf_mmap__write_tail(struct perf_mmap *md,
+                                        unsigned long tail)
+{
+       struct perf_event_mmap_page *pc = md->base;
+
+       /*
+        * ensure all reads are done before we write the tail out.
+        */
+       /* mb(); */
+       pc->data_tail = tail;
+}
+
 /*
  * prctl(PR_TASK_PERF_EVENTS_DISABLE) will (cheaply) disable all
  * counters in the current task.