libperf: Adopt perf_mmap__consume() function from tools/perf

Move perf_mmap__consume() vrom tools/perf to libperf and export it in
the perf/mmap.h header.

Move also the needed helpers perf_mmap__write_tail(),
perf_mmap__read_head() and perf_mmap__empty().

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191007125344.14268-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 11 insertions, 39 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 4394a5a10ce9..34ba47b9896b 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -42,6 +42,7 @@
 #include <perf/evlist.h>
 #include <perf/evsel.h>
 #include <perf/cpumap.h>
+#include <perf/mmap.h>
 
 #include <internal/xyarray.h>
 
@@ -1818,7 +1819,7 @@ static void *perf_evlist__poll_thread(void *arg)
 				else
 					pr_warning("cannot locate proper evsel for the side band event\n");
 
-				perf_mmap__consume(map);
+				perf_mmap__consume(&map->core);
 				got_data = true;
 			}
 			perf_mmap__read_done(map);
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index f246dd403507..abe7cbe6c95f 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -13,6 +13,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h> // sysconf()
+#include <perf/mmap.h>
 #ifdef HAVE_LIBNUMA_SUPPORT
 #include <numaif.h>
 #endif
@@ -95,7 +96,7 @@ union perf_event *perf_mmap__read_event(struct mmap *map)
 
 	/* non-overwirte doesn't pause the ringbuffer */
 	if (!map->core.overwrite)
-		map->core.end = perf_mmap__read_head(map);
+		map->core.end = perf_mmap__read_head(&map->core);
 
 	event = perf_mmap__read(map, &map->core.start, map->core.end);
 
@@ -105,25 +106,6 @@ union perf_event *perf_mmap__read_event(struct mmap *map)
 	return event;
 }
 
-static bool perf_mmap__empty(struct mmap *map)
-{
-	struct perf_event_mmap_page *pc = map->core.base;
-
-	return perf_mmap__read_head(map) == map->core.prev && !pc->aux_size;
-}
-
-void perf_mmap__consume(struct mmap *map)
-{
-	if (!map->core.overwrite) {
-		u64 old = map->core.prev;
-
-		perf_mmap__write_tail(map, old);
-	}
-
-	if (refcount_read(&map->core.refcnt) == 1 && perf_mmap__empty(map))
-		perf_mmap__put(&map->core);
-}
-
 int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
 			       struct auxtrace_mmap_params *mp __maybe_unused,
 			       void *userpg __maybe_unused,
@@ -420,7 +402,7 @@ static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)
  */
 static int __perf_mmap__read_init(struct mmap *md)
 {
-	u64 head = perf_mmap__read_head(md);
+	u64 head = perf_mmap__read_head(&md->core);
 	u64 old = md->core.prev;
 	unsigned char *data = md->core.base + page_size;
 	unsigned long size;
@@ -437,7 +419,7 @@ static int __perf_mmap__read_init(struct mmap *md)
 			WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
 
 			md->core.prev = head;
-			perf_mmap__consume(md);
+			perf_mmap__consume(&md->core);
 			return -EAGAIN;
 		}
 
@@ -466,7 +448,7 @@ int perf_mmap__read_init(struct mmap *map)
 int perf_mmap__push(struct mmap *md, void *to,
 		    int push(struct mmap *map, void *to, void *buf, size_t size))
 {
-	u64 head = perf_mmap__read_head(md);
+	u64 head = perf_mmap__read_head(&md->core);
 	unsigned char *data = md->core.base + page_size;
 	unsigned long size;
 	void *buf;
@@ -499,7 +481,7 @@ int perf_mmap__push(struct mmap *md, void *to,
 	}
 
 	md->core.prev = head;
-	perf_mmap__consume(md);
+	perf_mmap__consume(&md->core);
 out:
 	return rc;
 }
@@ -518,5 +500,5 @@ void perf_mmap__read_done(struct mmap *map)
 	if (!refcount_read(&map->core.refcnt))
 		return;
 
-	map->core.prev = perf_mmap__read_head(map);
+	map->core.prev = perf_mmap__read_head(&map->core);
 }
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index 78e3c4436ce8..89fb93267ff1 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -45,18 +45,6 @@ struct mmap_params {
 int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu);
 void mmap__munmap(struct mmap *map);
 
-void perf_mmap__consume(struct mmap *map);
-
-static inline u64 perf_mmap__read_head(struct mmap *mm)
-{
-	return ring_buffer_read_head(mm->core.base);
-}
-
-static inline void perf_mmap__write_tail(struct mmap *md, u64 tail)
-{
-	ring_buffer_write_tail(md->core.base, tail);
-}
-
 union perf_event *perf_mmap__read_forward(struct mmap *map);
 
 union perf_event *perf_mmap__read_event(struct mmap *map);
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 02460362256d..82a4fa6c87bd 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -6,6 +6,7 @@
 #include <linux/err.h>
 #include <perf/cpumap.h>
 #include <traceevent/event-parse.h>
+#include <perf/mmap.h>
 #include "evlist.h"
 #include "callchain.h"
 #include "evsel.h"
@@ -1045,7 +1046,7 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 		err = perf_evsel__parse_sample(evsel, event, &pevent->sample);
 
 		/* Consume the even only after we parsed it out. */
-		perf_mmap__consume(md);
+		perf_mmap__consume(&md->core);
 
 		if (err)
 			return PyErr_Format(PyExc_OSError,