[PATCH 45/73] libperf: Add perf_mmap__put function

From: Jiri Olsa
Date: Fri Sep 13 2019 - 09:25:55 EST


Move perf_mmap__put function under libperf.

Once perf_mmap__put is moved, we need a way to call
application related unmap code (AIO and aux related
code for eprf), when the map goes away.

Adding perf_mmap::unmap callback to do that.

The unmap path from perf is:

perf_mmap__put (libperf)
perf_mmap__munmap (libperf)
map->unmap_cb -> perf_mmap__unmap_cb (perf)
mmap__munmap (perf)

Link: http://lkml.kernel.org/n/tip-bl2yh297jg6tbsxo94px5fdm@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 4 ++--
tools/perf/lib/include/internal/mmap.h | 31 ++++++++++++++++----------
tools/perf/lib/mmap.c | 14 +++++++++++-
tools/perf/util/evlist.c | 17 +++++++++-----
tools/perf/util/mmap.c | 11 +--------
tools/perf/util/mmap.h | 2 --
6 files changed, 47 insertions(+), 32 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 82f6bd6b1adc..df0f2eceb359 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -194,7 +194,7 @@ static int record__aio_complete(struct mmap *md, struct aiocb *cblock)
* every aio write request started in record__aio_push() so
* decrement it because the request is now complete.
*/
- perf_mmap__put(md);
+ perf_mmap__put(&md->core);
rc = 1;
} else {
/*
@@ -329,7 +329,7 @@ static int record__aio_push(struct record *rec, struct mmap *map, off_t *off)
* map->refcount is decremented in record__aio_complete() after
* aio write operation finishes successfully.
*/
- perf_mmap__put(map);
+ perf_mmap__put(&map->core);
}

return ret;
diff --git a/tools/perf/lib/include/internal/mmap.h b/tools/perf/lib/include/internal/mmap.h
index 5c9ba00e67e1..cc0a5995cd3c 100644
--- a/tools/perf/lib/include/internal/mmap.h
+++ b/tools/perf/lib/include/internal/mmap.h
@@ -10,23 +10,28 @@
/* perf sample has 16 bits size limit */
#define PERF_SAMPLE_MAX_SIZE (1 << 16)

+struct perf_mmap;
+
+typedef void (*libperf_unmap_cb_t)(struct perf_mmap *map);
+
/**
* struct perf_mmap - perf's ring buffer mmap details
*
* @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
*/
struct perf_mmap {
- void *base;
- int mask;
- int fd;
- int cpu;
- refcount_t refcnt;
- u64 prev;
- u64 start;
- u64 end;
- bool overwrite;
- u64 flush;
- char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
+ void *base;
+ int mask;
+ int fd;
+ int cpu;
+ refcount_t refcnt;
+ u64 prev;
+ u64 start;
+ u64 end;
+ bool overwrite;
+ u64 flush;
+ libperf_unmap_cb_t unmap_cb;
+ char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
};

struct perf_mmap_param {
@@ -36,10 +41,12 @@ struct perf_mmap_param {

size_t perf_mmap__mmap_len(struct perf_mmap *map);

-void perf_mmap__init(struct perf_mmap *map, bool overwrite);
+void perf_mmap__init(struct perf_mmap *map, bool overwrite,
+ libperf_unmap_cb_t unmap_cb);
int perf_mmap__mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
int fd, int cpu);
void perf_mmap__munmap(struct perf_mmap *map);
void perf_mmap__get(struct perf_mmap *map);
+void perf_mmap__put(struct perf_mmap *map);

#endif /* __LIBPERF_INTERNAL_MMAP_H */
diff --git a/tools/perf/lib/mmap.c b/tools/perf/lib/mmap.c
index 6eb228d89206..ea46f325fa98 100644
--- a/tools/perf/lib/mmap.c
+++ b/tools/perf/lib/mmap.c
@@ -3,10 +3,12 @@
#include <internal/mmap.h>
#include <internal/lib.h>

-void perf_mmap__init(struct perf_mmap *map, bool overwrite)
+void perf_mmap__init(struct perf_mmap *map, bool overwrite,
+ libperf_unmap_cb_t unmap_cb)
{
map->fd = -1;
map->overwrite = overwrite;
+ map->unmap_cb = unmap_cb;
refcount_set(&map->refcnt, 0);
}

@@ -40,9 +42,19 @@ void perf_mmap__munmap(struct perf_mmap *map)
map->fd = -1;
refcount_set(&map->refcnt, 0);
}
+ if (map && map->unmap_cb)
+ map->unmap_cb(map);
}

void perf_mmap__get(struct perf_mmap *map)
{
refcount_inc(&map->refcnt);
}
+
+void perf_mmap__put(struct perf_mmap *map)
+{
+ BUG_ON(map->base && refcount_read(&map->refcnt) == 0);
+
+ if (refcount_dec_and_test(&map->refcnt))
+ perf_mmap__munmap(map);
+}
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 22165862f587..f1af59df1167 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -408,7 +408,7 @@ static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
struct mmap *map = fda->priv[fd].ptr;

if (map)
- perf_mmap__put(map);
+ perf_mmap__put(&map->core);
}

int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
@@ -576,11 +576,11 @@ static void evlist__munmap_nofree(struct evlist *evlist)

if (evlist->mmap)
for (i = 0; i < evlist->core.nr_mmaps; i++)
- mmap__munmap(&evlist->mmap[i]);
+ perf_mmap__munmap(&evlist->mmap[i].core);

if (evlist->overwrite_mmap)
for (i = 0; i < evlist->core.nr_mmaps; i++)
- mmap__munmap(&evlist->overwrite_mmap[i]);
+ perf_mmap__munmap(&evlist->overwrite_mmap[i].core);
}

void evlist__munmap(struct evlist *evlist)
@@ -590,6 +590,13 @@ void evlist__munmap(struct evlist *evlist)
zfree(&evlist->overwrite_mmap);
}

+static void perf_mmap__unmap_cb(struct perf_mmap *map)
+{
+ struct mmap *m = container_of(map, struct mmap, core);
+
+ mmap__munmap(m);
+}
+
static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
bool overwrite)
{
@@ -613,7 +620,7 @@ static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
* Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
* thus does perf_mmap__get() on it.
*/
- perf_mmap__init(&map[i].core, overwrite);
+ perf_mmap__init(&map[i].core, overwrite, perf_mmap__unmap_cb);
}

return map;
@@ -690,7 +697,7 @@ static int evlist__mmap_per_evsel(struct evlist *evlist, int idx,
*/
if (!evsel->core.system_wide &&
perf_evlist__add_pollfd(&evlist->core, fd, &maps[idx], revent) < 0) {
- perf_mmap__put(&maps[idx]);
+ perf_mmap__put(&maps[idx].core);
return -1;
}

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index eb77141dbfca..b904a7a57fdf 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -109,14 +109,6 @@ static bool perf_mmap__empty(struct mmap *map)
return perf_mmap__read_head(map) == map->core.prev && !map->auxtrace_mmap.base;
}

-void perf_mmap__put(struct mmap *map)
-{
- BUG_ON(map->core.base && refcount_read(&map->core.refcnt) == 0);
-
- if (refcount_dec_and_test(&map->core.refcnt))
- mmap__munmap(map);
-}
-
void perf_mmap__consume(struct mmap *map)
{
if (!map->core.overwrite) {
@@ -126,7 +118,7 @@ void perf_mmap__consume(struct mmap *map)
}

if (refcount_read(&map->core.refcnt) == 1 && perf_mmap__empty(map))
- perf_mmap__put(map);
+ perf_mmap__put(&map->core);
}

int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
@@ -307,7 +299,6 @@ static void perf_mmap__aio_munmap(struct mmap *map __maybe_unused)

void mmap__munmap(struct mmap *map)
{
- perf_mmap__munmap(&map->core);
perf_mmap__aio_munmap(map);
if (map->data != NULL) {
munmap(map->data, mmap__mmap_len(map));
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index 852f1ec20787..8a8f99cc7ecd 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -73,8 +73,6 @@ 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__put(struct mmap *map);
-
void perf_mmap__consume(struct mmap *map);

static inline u64 perf_mmap__read_head(struct mmap *mm)
--
2.21.0