[PATCH 51/69] libperf: Adopt perf_mmap__read_init() from tools/perf

From: Arnaldo Carvalho de Melo
Date: Fri Oct 11 2019 - 16:10:54 EST


From: Jiri Olsa <jolsa@xxxxxxxxxx>

Move perf_mmap__read_init() from tools/perf to libperf and export it in
perf/mmap.h header.

And add pr_debug2()/pr_debug3() macros support, because the code is
using them.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Michael Petlan <mpetlan@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20191007125344.14268-11-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/arch/x86/tests/perf-time-to-tsc.c | 2 +-
tools/perf/builtin-kvm.c | 2 +-
tools/perf/builtin-top.c | 2 +-
tools/perf/builtin-trace.c | 2 +-
tools/perf/lib/include/perf/core.h | 2 +
tools/perf/lib/include/perf/mmap.h | 1 +
tools/perf/lib/internal.h | 2 +
tools/perf/lib/libperf.map | 1 +
tools/perf/lib/mmap.c | 84 ++++++++++++++++++++
tools/perf/tests/backward-ring-buffer.c | 2 +-
tools/perf/tests/bpf.c | 2 +-
tools/perf/tests/code-reading.c | 2 +-
tools/perf/tests/keep-tracking.c | 2 +-
tools/perf/tests/mmap-basic.c | 2 +-
tools/perf/tests/openat-syscall-tp-fields.c | 2 +-
tools/perf/tests/perf-record.c | 2 +-
tools/perf/tests/sw-clock.c | 2 +-
tools/perf/tests/switch-tracking.c | 2 +-
tools/perf/tests/task-exit.c | 2 +-
tools/perf/util/evlist.c | 2 +-
tools/perf/util/mmap.c | 82 +------------------
tools/perf/util/mmap.h | 1 -
tools/perf/util/python.c | 2 +-
23 files changed, 107 insertions(+), 98 deletions(-)

diff --git a/tools/perf/arch/x86/tests/perf-time-to-tsc.c b/tools/perf/arch/x86/tests/perf-time-to-tsc.c
index 3397898824f6..6a0c3ff78e01 100644
--- a/tools/perf/arch/x86/tests/perf-time-to-tsc.c
+++ b/tools/perf/arch/x86/tests/perf-time-to-tsc.c
@@ -118,7 +118,7 @@ int test__perf_time_to_tsc(struct test *test __maybe_unused, int subtest __maybe

for (i = 0; i < evlist->core.nr_mmaps; i++) {
md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 0c04c4c6c1eb..b6a8078dd446 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -760,7 +760,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,

*mmap_time = ULLONG_MAX;
md = &evlist->mmap[idx];
- err = perf_mmap__read_init(md);
+ err = perf_mmap__read_init(&md->core);
if (err < 0)
return (err == -EAGAIN) ? 0 : -1;

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5fcf15799415..4a4bb7b20c39 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -870,7 +870,7 @@ static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
union perf_event *event;

md = opts->overwrite ? &evlist->overwrite_mmap[idx] : &evlist->mmap[idx];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
return;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 6a5708438566..cd69d68e7f1d 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3801,7 +3801,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
struct mmap *md;

md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/lib/include/perf/core.h b/tools/perf/lib/include/perf/core.h
index cfd70e720c1c..2a80e4b6f819 100644
--- a/tools/perf/lib/include/perf/core.h
+++ b/tools/perf/lib/include/perf/core.h
@@ -12,6 +12,8 @@ enum libperf_print_level {
LIBPERF_WARN,
LIBPERF_INFO,
LIBPERF_DEBUG,
+ LIBPERF_DEBUG2,
+ LIBPERF_DEBUG3,
};

typedef int (*libperf_print_fn_t)(enum libperf_print_level level,
diff --git a/tools/perf/lib/include/perf/mmap.h b/tools/perf/lib/include/perf/mmap.h
index d3678d1834d9..646e9052b003 100644
--- a/tools/perf/lib/include/perf/mmap.h
+++ b/tools/perf/lib/include/perf/mmap.h
@@ -7,5 +7,6 @@
struct perf_mmap;

LIBPERF_API void perf_mmap__consume(struct perf_mmap *map);
+LIBPERF_API int perf_mmap__read_init(struct perf_mmap *map);

#endif /* __LIBPERF_MMAP_H */
diff --git a/tools/perf/lib/internal.h b/tools/perf/lib/internal.h
index dc92f241732e..37db745e1502 100644
--- a/tools/perf/lib/internal.h
+++ b/tools/perf/lib/internal.h
@@ -14,5 +14,7 @@ do { \
#define pr_warning(fmt, ...) __pr(LIBPERF_WARN, fmt, ##__VA_ARGS__)
#define pr_info(fmt, ...) __pr(LIBPERF_INFO, fmt, ##__VA_ARGS__)
#define pr_debug(fmt, ...) __pr(LIBPERF_DEBUG, fmt, ##__VA_ARGS__)
+#define pr_debug2(fmt, ...) __pr(LIBPERF_DEBUG2, fmt, ##__VA_ARGS__)
+#define pr_debug3(fmt, ...) __pr(LIBPERF_DEBUG3, fmt, ##__VA_ARGS__)

#endif /* __LIBPERF_INTERNAL_H */
diff --git a/tools/perf/lib/libperf.map b/tools/perf/lib/libperf.map
index d7b327f224e2..bc3fbb213a3e 100644
--- a/tools/perf/lib/libperf.map
+++ b/tools/perf/lib/libperf.map
@@ -41,6 +41,7 @@ LIBPERF_0.0.1 {
perf_evlist__set_maps;
perf_evlist__poll;
perf_mmap__consume;
+ perf_mmap__read_init;
local:
*;
};
diff --git a/tools/perf/lib/mmap.c b/tools/perf/lib/mmap.c
index 4cada1c89fdb..fdbc6c550dea 100644
--- a/tools/perf/lib/mmap.c
+++ b/tools/perf/lib/mmap.c
@@ -1,11 +1,15 @@
// SPDX-License-Identifier: GPL-2.0
#include <sys/mman.h>
+#include <inttypes.h>
+#include <asm/bug.h>
+#include <errno.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>
+#include "internal.h"

void perf_mmap__init(struct perf_mmap *map, bool overwrite,
libperf_unmap_cb_t unmap_cb)
@@ -91,3 +95,83 @@ void perf_mmap__consume(struct perf_mmap *map)
if (refcount_read(&map->refcnt) == 1 && perf_mmap__empty(map))
perf_mmap__put(map);
}
+
+static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)
+{
+ struct perf_event_header *pheader;
+ u64 evt_head = *start;
+ int size = mask + 1;
+
+ pr_debug2("%s: buf=%p, start=%"PRIx64"\n", __func__, buf, *start);
+ pheader = (struct perf_event_header *)(buf + (*start & mask));
+ while (true) {
+ if (evt_head - *start >= (unsigned int)size) {
+ pr_debug("Finished reading overwrite ring buffer: rewind\n");
+ if (evt_head - *start > (unsigned int)size)
+ evt_head -= pheader->size;
+ *end = evt_head;
+ return 0;
+ }
+
+ pheader = (struct perf_event_header *)(buf + (evt_head & mask));
+
+ if (pheader->size == 0) {
+ pr_debug("Finished reading overwrite ring buffer: get start\n");
+ *end = evt_head;
+ return 0;
+ }
+
+ evt_head += pheader->size;
+ pr_debug3("move evt_head: %"PRIx64"\n", evt_head);
+ }
+ WARN_ONCE(1, "Shouldn't get here\n");
+ return -1;
+}
+
+/*
+ * Report the start and end of the available data in ringbuffer
+ */
+static int __perf_mmap__read_init(struct perf_mmap *md)
+{
+ u64 head = perf_mmap__read_head(md);
+ u64 old = md->prev;
+ unsigned char *data = md->base + page_size;
+ unsigned long size;
+
+ md->start = md->overwrite ? head : old;
+ md->end = md->overwrite ? old : head;
+
+ if ((md->end - md->start) < md->flush)
+ return -EAGAIN;
+
+ size = md->end - md->start;
+ if (size > (unsigned long)(md->mask) + 1) {
+ if (!md->overwrite) {
+ WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
+
+ md->prev = head;
+ perf_mmap__consume(md);
+ return -EAGAIN;
+ }
+
+ /*
+ * Backward ring buffer is full. We still have a chance to read
+ * most of data from it.
+ */
+ if (overwrite_rb_find_range(data, md->mask, &md->start, &md->end))
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int perf_mmap__read_init(struct perf_mmap *map)
+{
+ /*
+ * Check if event was unmapped due to a POLLHUP/POLLERR.
+ */
+ if (!refcount_read(&map->refcnt))
+ return -ENOENT;
+
+ return __perf_mmap__read_init(map);
+}
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index 13f9a060361a..ff3a986983ab 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -38,7 +38,7 @@ static int count_samples(struct evlist *evlist, int *sample_count,
struct mmap *map = &evlist->overwrite_mmap[i];
union perf_event *event;

- perf_mmap__read_init(map);
+ perf_mmap__read_init(&map->core);
while ((event = perf_mmap__read_event(map)) != NULL) {
const u32 type = event->header.type;

diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index 6f0d239f8277..73d26c63d624 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -185,7 +185,7 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
struct mmap *md;

md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index b5a57bb54c25..cf992e0b27ff 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -426,7 +426,7 @@ static int process_events(struct machine *machine, struct evlist *evlist,

for (i = 0; i < evlist->core.nr_mmaps; i++) {
md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index 31c005e07b17..e85da7e77269 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -39,7 +39,7 @@ static int find_comm(struct evlist *evlist, const char *comm)
found = 0;
for (i = 0; i < evlist->core.nr_mmaps; i++) {
md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;
while ((event = perf_mmap__read_event(md)) != NULL) {
if (event->header.type == PERF_RECORD_COMM &&
diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index b176acc4f52e..77f42f0ac15d 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -114,7 +114,7 @@ int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unuse
}

md = &evlist->mmap[0];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
goto out_init;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/openat-syscall-tp-fields.c b/tools/perf/tests/openat-syscall-tp-fields.c
index bbf8ba320721..d6a563120d93 100644
--- a/tools/perf/tests/openat-syscall-tp-fields.c
+++ b/tools/perf/tests/openat-syscall-tp-fields.c
@@ -93,7 +93,7 @@ int test__syscall_openat_tp_fields(struct test *test __maybe_unused, int subtest
struct mmap *md;

md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index 6ebbcc65749e..2587cb8b2c0f 100644
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -171,7 +171,7 @@ int test__PERF_RECORD(struct test *test __maybe_unused, int subtest __maybe_unus
struct mmap *md;

md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/sw-clock.c b/tools/perf/tests/sw-clock.c
index 1aeb558010c1..808669507c30 100644
--- a/tools/perf/tests/sw-clock.c
+++ b/tools/perf/tests/sw-clock.c
@@ -100,7 +100,7 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
evlist__disable(evlist);

md = &evlist->mmap[0];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
goto out_init;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
index 55728b3da057..bedfdec34972 100644
--- a/tools/perf/tests/switch-tracking.c
+++ b/tools/perf/tests/switch-tracking.c
@@ -270,7 +270,7 @@ static int process_events(struct evlist *evlist,

for (i = 0; i < evlist->core.nr_mmaps; i++) {
md = &evlist->mmap[i];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
continue;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c
index a0f689594848..035d42375d4b 100644
--- a/tools/perf/tests/task-exit.c
+++ b/tools/perf/tests/task-exit.c
@@ -118,7 +118,7 @@ int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused

retry:
md = &evlist->mmap[0];
- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
goto out_init;

while ((event = perf_mmap__read_event(md)) != NULL) {
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 34ba47b9896b..d9a4a4b188ed 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1809,7 +1809,7 @@ static void *perf_evlist__poll_thread(void *arg)
struct mmap *map = &evlist->mmap[i];
union perf_event *event;

- if (perf_mmap__read_init(map))
+ if (perf_mmap__read_init(&map->core))
continue;
while ((event = perf_mmap__read_event(map)) != NULL) {
struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index abe7cbe6c95f..59379118c2f1 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -365,86 +365,6 @@ int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu)
return perf_mmap__aio_mmap(map, mp);
}

-static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)
-{
- struct perf_event_header *pheader;
- u64 evt_head = *start;
- int size = mask + 1;
-
- pr_debug2("%s: buf=%p, start=%"PRIx64"\n", __func__, buf, *start);
- pheader = (struct perf_event_header *)(buf + (*start & mask));
- while (true) {
- if (evt_head - *start >= (unsigned int)size) {
- pr_debug("Finished reading overwrite ring buffer: rewind\n");
- if (evt_head - *start > (unsigned int)size)
- evt_head -= pheader->size;
- *end = evt_head;
- return 0;
- }
-
- pheader = (struct perf_event_header *)(buf + (evt_head & mask));
-
- if (pheader->size == 0) {
- pr_debug("Finished reading overwrite ring buffer: get start\n");
- *end = evt_head;
- return 0;
- }
-
- evt_head += pheader->size;
- pr_debug3("move evt_head: %"PRIx64"\n", evt_head);
- }
- WARN_ONCE(1, "Shouldn't get here\n");
- return -1;
-}
-
-/*
- * Report the start and end of the available data in ringbuffer
- */
-static int __perf_mmap__read_init(struct mmap *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;
-
- md->core.start = md->core.overwrite ? head : old;
- md->core.end = md->core.overwrite ? old : head;
-
- if ((md->core.end - md->core.start) < md->core.flush)
- return -EAGAIN;
-
- size = md->core.end - md->core.start;
- if (size > (unsigned long)(md->core.mask) + 1) {
- if (!md->core.overwrite) {
- WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
-
- md->core.prev = head;
- perf_mmap__consume(&md->core);
- return -EAGAIN;
- }
-
- /*
- * Backward ring buffer is full. We still have a chance to read
- * most of data from it.
- */
- if (overwrite_rb_find_range(data, md->core.mask, &md->core.start, &md->core.end))
- return -EINVAL;
- }
-
- return 0;
-}
-
-int perf_mmap__read_init(struct mmap *map)
-{
- /*
- * Check if event was unmapped due to a POLLHUP/POLLERR.
- */
- if (!refcount_read(&map->core.refcnt))
- return -ENOENT;
-
- return __perf_mmap__read_init(map);
-}
-
int perf_mmap__push(struct mmap *md, void *to,
int push(struct mmap *map, void *to, void *buf, size_t size))
{
@@ -454,7 +374,7 @@ int perf_mmap__push(struct mmap *md, void *to,
void *buf;
int rc = 0;

- rc = perf_mmap__read_init(md);
+ rc = perf_mmap__read_init(&md->core);
if (rc < 0)
return (rc == -EAGAIN) ? 1 : -1;

diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index 89fb93267ff1..6d818ef51f05 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -54,6 +54,5 @@ int perf_mmap__push(struct mmap *md, void *to,

size_t mmap__mmap_len(struct mmap *map);

-int perf_mmap__read_init(struct mmap *md);
void perf_mmap__read_done(struct mmap *map);
#endif /*__PERF_MMAP_H */
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 82a4fa6c87bd..64eec2a239d4 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1023,7 +1023,7 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
if (!md)
return NULL;

- if (perf_mmap__read_init(md) < 0)
+ if (perf_mmap__read_init(&md->core) < 0)
goto end;

event = perf_mmap__read_event(md);
--
2.21.0