Adding perf_evlist_mmap_ops::mmap callback to be called
in mmap_per_evsel to actually mmap the map.
Adding libperf's perf_evlist__mmap_cb_mmap function as
libperf's mmap callback.
New mmaped map gets refcount set to 2 in mmap__mmap,
we follow that in mmap callback. We will move this to
common place after we switch to perf_evlist__mmap.
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Jiri Olsa <[email protected]>
---
tools/perf/lib/evlist.c | 29 +++++++++++++++++++++---
tools/perf/lib/include/internal/evlist.h | 3 +++
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/tools/perf/lib/evlist.c b/tools/perf/lib/evlist.c
index 4f49de5e8f7c..b69722627779 100644
--- a/tools/perf/lib/evlist.c
+++ b/tools/perf/lib/evlist.c
@@ -358,6 +358,28 @@ perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
+static int
+perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
+ int output, int cpu)
+{
+ /*
+ * The last one will be done at perf_mmap__consume(), so that we
+ * make sure we don't prevent tools from consuming every last event in
+ * the ring buffer.
+ *
+ * I.e. we can get the POLLHUP meaning that the fd doesn't exist
+ * anymore, but the last events for it are still in the ring buffer,
+ * waiting to be consumed.
+ *
+ * Tools can chose to ignore this at their own discretion, but the
+ * evlist layer can't just drop it when filtering events in
+ * perf_evlist__filter_pollfd().
+ */
+ refcount_set(&map->refcnt, 2);
+
+ return perf_mmap__mmap(map, mp, output, cpu);
+}
+
static int
mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
int idx, struct perf_mmap_param *mp, int cpu_idx,
@@ -396,7 +418,7 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
if (*output == -1) {
*output = fd;
- if (perf_mmap__mmap(map, mp, *output, evlist_cpu) < 0)
+ if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
return -1;
} else {
if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
@@ -488,7 +510,7 @@ int perf_evlist__mmap_ops(struct perf_evlist *evlist,
const struct perf_cpu_map *cpus = evlist->cpus;
const struct perf_thread_map *threads = evlist->threads;
- if (!ops || !ops->get)
+ if (!ops || !ops->get || !ops->mmap)
return -EINVAL;
if (!evlist->mmap)
@@ -513,7 +535,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
{
struct perf_mmap_param mp;
struct perf_evlist_mmap_ops ops = {
- .get = perf_evlist__mmap_cb_get,
+ .get = perf_evlist__mmap_cb_get,
+ .mmap = perf_evlist__mmap_cb_mmap,
};
evlist->mmap_len = (pages + 1) * page_size;
diff --git a/tools/perf/lib/include/internal/evlist.h b/tools/perf/lib/include/internal/evlist.h
index 9bc3a21643ea..b2019700cdc0 100644
--- a/tools/perf/lib/include/internal/evlist.h
+++ b/tools/perf/lib/include/internal/evlist.h
@@ -31,10 +31,13 @@ typedef void
(*perf_evlist_mmap__cb_idx_t)(struct perf_evlist*, struct perf_mmap_param*, int, bool);
typedef struct perf_mmap*
(*perf_evlist_mmap__cb_get_t)(struct perf_evlist*, bool, int);
+typedef int
+(*perf_evlist_mmap__cb_mmap_t)(struct perf_mmap*, struct perf_mmap_param*, int, int);
struct perf_evlist_mmap_ops {
perf_evlist_mmap__cb_idx_t idx;
perf_evlist_mmap__cb_get_t get;
+ perf_evlist_mmap__cb_mmap_t mmap;
};
int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);
--
2.21.0
The following commit has been merged into the perf/core branch of tip:
Commit-ID: b5911e7ac28cb34f21b7380915ce98518078f114
Gitweb: https://git.kernel.org/tip/b5911e7ac28cb34f21b7380915ce98518078f114
Author: Jiri Olsa <[email protected]>
AuthorDate: Mon, 07 Oct 2019 14:53:25 +02:00
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitterDate: Thu, 10 Oct 2019 12:22:21 -03:00
libperf: Introduce perf_evlist_mmap_ops::mmap callback
Add the perf_evlist_mmap_ops::mmap callback to be called in
mmap_per_evsel() to actually mmap the map.
Add libperf's perf_evlist__mmap_cb_mmap() function as libperf's mmap
callback.
New mmaped map gets refcount set to 2 in mmap__mmap(), we follow that in
mmap callback. We will move this to common place after we switch to
perf_evlist__mmap().
Signed-off-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/lib/evlist.c | 29 ++++++++++++++++++++---
tools/perf/lib/include/internal/evlist.h | 3 ++-
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/tools/perf/lib/evlist.c b/tools/perf/lib/evlist.c
index 4f49de5..b697226 100644
--- a/tools/perf/lib/evlist.c
+++ b/tools/perf/lib/evlist.c
@@ -359,6 +359,28 @@ perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
static int
+perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
+ int output, int cpu)
+{
+ /*
+ * The last one will be done at perf_mmap__consume(), so that we
+ * make sure we don't prevent tools from consuming every last event in
+ * the ring buffer.
+ *
+ * I.e. we can get the POLLHUP meaning that the fd doesn't exist
+ * anymore, but the last events for it are still in the ring buffer,
+ * waiting to be consumed.
+ *
+ * Tools can chose to ignore this at their own discretion, but the
+ * evlist layer can't just drop it when filtering events in
+ * perf_evlist__filter_pollfd().
+ */
+ refcount_set(&map->refcnt, 2);
+
+ return perf_mmap__mmap(map, mp, output, cpu);
+}
+
+static int
mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
int idx, struct perf_mmap_param *mp, int cpu_idx,
int thread, int *_output, int *_output_overwrite)
@@ -396,7 +418,7 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
if (*output == -1) {
*output = fd;
- if (perf_mmap__mmap(map, mp, *output, evlist_cpu) < 0)
+ if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
return -1;
} else {
if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
@@ -488,7 +510,7 @@ int perf_evlist__mmap_ops(struct perf_evlist *evlist,
const struct perf_cpu_map *cpus = evlist->cpus;
const struct perf_thread_map *threads = evlist->threads;
- if (!ops || !ops->get)
+ if (!ops || !ops->get || !ops->mmap)
return -EINVAL;
if (!evlist->mmap)
@@ -513,7 +535,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
{
struct perf_mmap_param mp;
struct perf_evlist_mmap_ops ops = {
- .get = perf_evlist__mmap_cb_get,
+ .get = perf_evlist__mmap_cb_get,
+ .mmap = perf_evlist__mmap_cb_mmap,
};
evlist->mmap_len = (pages + 1) * page_size;
diff --git a/tools/perf/lib/include/internal/evlist.h b/tools/perf/lib/include/internal/evlist.h
index 9bc3a21..b201970 100644
--- a/tools/perf/lib/include/internal/evlist.h
+++ b/tools/perf/lib/include/internal/evlist.h
@@ -31,10 +31,13 @@ typedef void
(*perf_evlist_mmap__cb_idx_t)(struct perf_evlist*, struct perf_mmap_param*, int, bool);
typedef struct perf_mmap*
(*perf_evlist_mmap__cb_get_t)(struct perf_evlist*, bool, int);
+typedef int
+(*perf_evlist_mmap__cb_mmap_t)(struct perf_mmap*, struct perf_mmap_param*, int, int);
struct perf_evlist_mmap_ops {
perf_evlist_mmap__cb_idx_t idx;
perf_evlist_mmap__cb_get_t get;
+ perf_evlist_mmap__cb_mmap_t mmap;
};
int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);