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>

tools/perf/arch/x86/tests/perf-time-to-tsc.c

@@ -9,6 +9,7 @@
 #include <sys/prctl.h>
 #include <perf/cpumap.h>
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 #include "debug.h"
 #include "parse-events.h"
@@ -139,7 +140,7 @@ int test__perf_time_to_tsc(struct test *test __maybe_unused, int subtest __maybe
 				comm2_time = sample.time;
 			}
 next_event:
-			perf_mmap__consume(md);
+			perf_mmap__consume(&md->core);
 		}
 		perf_mmap__read_done(md);
 	}

tools/perf/builtin-kvm.c

@@ -46,6 +46,7 @@
 #include <semaphore.h>
 #include <signal.h>
 #include <math.h>
+#include <perf/mmap.h>
 
 static const char *get_filename_for_perf_kvm(void)
 {
@@ -766,7 +767,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
 	while ((event = perf_mmap__read_event(md)) != NULL) {
 		err = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
 		if (err) {
-			perf_mmap__consume(md);
+			perf_mmap__consume(&md->core);
 			pr_err("Failed to parse sample\n");
 			return -1;
 		}
@@ -776,7 +777,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
 		 * FIXME: Here we can't consume the event, as perf_session__queue_event will
 		 *        point to it, and it'll get possibly overwritten by the kernel.
 		 */
-		perf_mmap__consume(md);
+		perf_mmap__consume(&md->core);
 
 		if (err) {
 			pr_err("Failed to enqueue sample: %d\n", err);

tools/perf/builtin-top.c

@@ -82,6 +82,7 @@
 #include <linux/err.h>
 
 #include <linux/ctype.h>
+#include <perf/mmap.h>
 
 static volatile int done;
 static volatile int resize;
@@ -883,7 +884,7 @@ static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
 		if (ret)
 			break;
 
-		perf_mmap__consume(md);
+		perf_mmap__consume(&md->core);
 
 		if (top->qe.rotate) {
 			pthread_mutex_lock(&top->qe.mutex);

tools/perf/builtin-trace.c

@@ -77,6 +77,7 @@
 #include <sys/sysmacros.h>
 
 #include <linux/ctype.h>
+#include <perf/mmap.h>
 
 #ifndef O_CLOEXEC
 # define O_CLOEXEC		02000000
@@ -3810,7 +3811,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 			if (err)
 				goto out_disable;
 
-			perf_mmap__consume(md);
+			perf_mmap__consume(&md->core);
 
 			if (interrupted)
 				goto out_disable;

tools/perf/lib/Makefile

@@ -172,8 +172,9 @@ install_headers:
 		$(call do_install,include/perf/cpumap.h,$(prefix)/include/perf,644); \
 		$(call do_install,include/perf/threadmap.h,$(prefix)/include/perf,644); \
 		$(call do_install,include/perf/evlist.h,$(prefix)/include/perf,644); \
-		$(call do_install,include/perf/evsel.h,$(prefix)/include/perf,644);
-		$(call do_install,include/perf/event.h,$(prefix)/include/perf,644);
+		$(call do_install,include/perf/evsel.h,$(prefix)/include/perf,644); \
+		$(call do_install,include/perf/event.h,$(prefix)/include/perf,644); \
+		$(call do_install,include/perf/mmap.h,$(prefix)/include/perf,644);
 
 install_pkgconfig: $(LIBPERF_PC)
 	$(call QUIET_INSTALL, $(LIBPERF_PC)) \

tools/perf/lib/include/internal/mmap.h

@@ -49,4 +49,6 @@ void perf_mmap__munmap(struct perf_mmap *map);
 void perf_mmap__get(struct perf_mmap *map);
 void perf_mmap__put(struct perf_mmap *map);
 
+u64 perf_mmap__read_head(struct perf_mmap *map);
+
 #endif /* __LIBPERF_INTERNAL_MMAP_H */

tools/perf/lib/include/perf/mmap.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LIBPERF_MMAP_H
+#define __LIBPERF_MMAP_H
+
+#include <perf/core.h>
+
+struct perf_mmap;
+
+LIBPERF_API void perf_mmap__consume(struct perf_mmap *map);
+
+#endif /* __LIBPERF_MMAP_H */

tools/perf/lib/libperf.map

@@ -40,6 +40,7 @@ LIBPERF_0.0.1 {
 		perf_evlist__next;
 		perf_evlist__set_maps;
 		perf_evlist__poll;
+		perf_mmap__consume;
 	local:
 		*;
 };

tools/perf/lib/mmap.c

@@ -1,5 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <sys/mman.h>
+#include <linux/ring_buffer.h>
+#include <linux/perf_event.h>
+#include <perf/mmap.h>
 #include <internal/mmap.h>
 #include <internal/lib.h>
 #include <linux/kernel.h>
@@ -59,3 +62,32 @@ void perf_mmap__put(struct perf_mmap *map)
 	if (refcount_dec_and_test(&map->refcnt))
 		perf_mmap__munmap(map);
 }
+
+static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
+{
+	ring_buffer_write_tail(md->base, tail);
+}
+
+u64 perf_mmap__read_head(struct perf_mmap *map)
+{
+	return ring_buffer_read_head(map->base);
+}
+
+static bool perf_mmap__empty(struct perf_mmap *map)
+{
+	struct perf_event_mmap_page *pc = map->base;
+
+	return perf_mmap__read_head(map) == map->prev && !pc->aux_size;
+}
+
+void perf_mmap__consume(struct perf_mmap *map)
+{
+	if (!map->overwrite) {
+		u64 old = map->prev;
+
+		perf_mmap__write_tail(map, old);
+	}
+
+	if (refcount_read(&map->refcnt) == 1 && perf_mmap__empty(map))
+		perf_mmap__put(map);
+}

tools/perf/tests/backward-ring-buffer.c

@@ -13,6 +13,7 @@
 #include "util/mmap.h"
 #include <errno.h>
 #include <linux/string.h>
+#include <perf/mmap.h>
 
 #define NR_ITERS 111
 

tools/perf/tests/bpf.c

@@ -15,6 +15,7 @@
 #include <linux/string.h>
 #include <api/fs/fs.h>
 #include <bpf/bpf.h>
+#include <perf/mmap.h>
 #include "tests.h"
 #include "llvm.h"
 #include "debug.h"

tools/perf/tests/code-reading.c

@@ -10,6 +10,7 @@
 #include <sys/param.h>
 #include <perf/cpumap.h>
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 #include "debug.h"
 #include "dso.h"
@@ -430,7 +431,7 @@ static int process_events(struct machine *machine, struct evlist *evlist,
 
 		while ((event = perf_mmap__read_event(md)) != NULL) {
 			ret = process_event(machine, evlist, event, state);
-			perf_mmap__consume(md);
+			perf_mmap__consume(&md->core);
 			if (ret < 0)
 				return ret;
 		}

tools/perf/tests/keep-tracking.c

@@ -5,6 +5,7 @@
 #include <sys/prctl.h>
 #include <perf/cpumap.h>
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 #include "debug.h"
 #include "parse-events.h"
@@ -46,7 +47,7 @@ static int find_comm(struct evlist *evlist, const char *comm)
 			    (pid_t)event->comm.tid == getpid() &&
 			    strcmp(event->comm.comm, comm) == 0)
 				found += 1;
-			perf_mmap__consume(md);
+			perf_mmap__consume(&md->core);
 		}
 		perf_mmap__read_done(md);
 	}

tools/perf/tests/mmap-basic.c

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 /*
  * This test will generate random numbers of calls to some getpid syscalls,
@@ -139,7 +140,7 @@ int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unuse
 			goto out_delete_evlist;
 		}
 		nr_events[evsel->idx]++;
-		perf_mmap__consume(md);
+		perf_mmap__consume(&md->core);
 	}
 	perf_mmap__read_done(md);
 

tools/perf/tests/openat-syscall-tp-fields.c

@@ -13,6 +13,7 @@
 #include "debug.h"
 #include "util/mmap.h"
 #include <errno.h>
+#include <perf/mmap.h>
 
 #ifndef O_DIRECTORY
 #define O_DIRECTORY    00200000
@@ -103,7 +104,7 @@ int test__syscall_openat_tp_fields(struct test *test __maybe_unused, int subtest
 				++nr_events;
 
 				if (type != PERF_RECORD_SAMPLE) {
-					perf_mmap__consume(md);
+					perf_mmap__consume(&md->core);
 					continue;
 				}
 

tools/perf/tests/perf-record.c

@@ -6,6 +6,7 @@
 #include <pthread.h>
 
 #include <sched.h>
+#include <perf/mmap.h>
 #include "evlist.h"
 #include "evsel.h"
 #include "debug.h"
@@ -276,7 +277,7 @@ int test__PERF_RECORD(struct test *test __maybe_unused, int subtest __maybe_unus
 					++errs;
 				}
 
-				perf_mmap__consume(md);
+				perf_mmap__consume(&md->core);
 			}
 			perf_mmap__read_done(md);
 		}

tools/perf/tests/sw-clock.c

@@ -15,6 +15,7 @@
 #include "util/mmap.h"
 #include "util/thread_map.h"
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 #define NR_LOOPS  10000000
 
@@ -117,7 +118,7 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
 		total_periods += sample.period;
 		nr_samples++;
 next_event:
-		perf_mmap__consume(md);
+		perf_mmap__consume(&md->core);
 	}
 	perf_mmap__read_done(md);
 

tools/perf/tests/switch-tracking.c

@@ -8,6 +8,7 @@
 #include <linux/zalloc.h>
 #include <perf/cpumap.h>
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 #include "debug.h"
 #include "parse-events.h"
@@ -275,7 +276,7 @@ static int process_events(struct evlist *evlist,
 		while ((event = perf_mmap__read_event(md)) != NULL) {
 			cnt += 1;
 			ret = add_event(evlist, &events, event);
-			 perf_mmap__consume(md);
+			 perf_mmap__consume(&md->core);
 			if (ret < 0)
 				goto out_free_nodes;
 		}

tools/perf/tests/task-exit.c

@@ -12,6 +12,7 @@
 #include <linux/string.h>
 #include <perf/cpumap.h>
 #include <perf/evlist.h>
+#include <perf/mmap.h>
 
 static int exited;
 static int nr_exit;
@@ -124,7 +125,7 @@ int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused
 		if (event->header.type == PERF_RECORD_EXIT)
 			nr_exit++;
 
-		perf_mmap__consume(md);
+		perf_mmap__consume(&md->core);
 	}
 	perf_mmap__read_done(md);
 

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);

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);
 }

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);

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,