[PATCH V2 02/10] perf script: Add dlfilter__filter_event_early()

Adrian Hunter
2021-06-27T13:18:11Z

filter_event_early() can be more than 30% faster than filter_event()
because it is called before internal filtering. In other respects it
is the same as filter_event(), except that it will be passed events
that have yet to be filtered out.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/Documentation/perf-dlfilter.txt | 13 +++++++----
tools/perf/builtin-script.c | 26 +++++++++++++++-------
tools/perf/util/dlfilter.c | 9 ++++++--
tools/perf/util/dlfilter.h | 21 +++++++++++++++--
tools/perf/util/perf_dlfilter.h | 6 +++++
5 files changed, 59 insertions(+), 16 deletions(-)

diff --git a/tools/perf/Documentation/perf-dlfilter.txt b/tools/perf/Documentation/perf-dlfilter.txt
index 15d5f4b01c97..aef1c32babd1 100644
--- a/tools/perf/Documentation/perf-dlfilter.txt
+++ b/tools/perf/Documentation/perf-dlfilter.txt
@@ -36,16 +36,17 @@ const struct perf_dlfilter_fns perf_dlfilter_fns;
int start(void **data, void *ctx);
int stop(void *data, void *ctx);
int filter_event(void *data, const struct perf_dlfilter_sample *sample, void *ctx);
+int filter_event_early(void *data, const struct perf_dlfilter_sample *sample, void *ctx);
----

If implemented, 'start' will be called at the beginning, before any
-calls to 'filter_event' . Return 0 to indicate success,
+calls to 'filter_event' or 'filter_event_early'. Return 0 to indicate success,
or return a negative error code. '*data' can be assigned for use by other
functions. 'ctx' is needed for calls to perf_dlfilter_fns, but most
perf_dlfilter_fns are not valid when called from 'start'.

If implemented, 'stop' will be called at the end, after any calls to
-'filter_event'. Return 0 to indicate success, or
+'filter_event' or 'filter_event_early'. Return 0 to indicate success, or
return a negative error code. 'data' is set by 'start'. 'ctx' is needed
for calls to perf_dlfilter_fns, but most perf_dlfilter_fns are not valid
when called from 'stop'.
@@ -55,10 +56,13 @@ Return 0 to keep the sample event, 1 to filter it out, or return a negative
error code. 'data' is set by 'start'. 'ctx' is needed for calls to
'perf_dlfilter_fns'.

+'filter_event_early' is the same as 'filter_event' except it is called before
+internal filtering.
+
The perf_dlfilter_sample structure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-'filter_event' is passed a perf_dlfilter_sample
+'filter_event' and 'filter_event_early' are passed a perf_dlfilter_sample
structure, which contains the following fields:
[source,c]
----
@@ -105,7 +109,8 @@ The perf_dlfilter_fns structure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The 'perf_dlfilter_fns' structure is populated with function pointers when the
-file is loaded. The functions can be called by 'filter_event'.
+file is loaded. The functions can be called by 'filter_event' or
+'filter_event_early'.

[source,c]
----
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index aaf2922643a0..e47affe674a5 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -2179,9 +2179,20 @@ static int process_sample_event(struct perf_tool *tool,
struct addr_location addr_al;
int ret = 0;

+ /* Set thread to NULL to indicate addr_al and al are not initialized */
+ addr_al.thread = NULL;
+ al.thread = NULL;
+
+ ret = dlfilter__filter_event_early(dlfilter, event, sample, evsel, machine, &al, &addr_al);
+ if (ret) {
+ if (ret > 0)
+ ret = 0;
+ goto out_put;
+ }
+
if (perf_time__ranges_skip_sample(scr->ptime_range, scr->range_num,
sample->time)) {
- return 0;
+ goto out_put;
}

if (debug_mode) {
@@ -2192,24 +2203,22 @@ static int process_sample_event(struct perf_tool *tool,
nr_unordered++;
}
last_timestamp = sample->time;
- return 0;
+ goto out_put;
}

if (filter_cpu(sample))
- return 0;
+ goto out_put;

if (machine__resolve(machine, &al, sample) < 0) {
pr_err("problem processing %d event, skipping it.\n",
event->header.type);
- return -1;
+ ret = -1;
+ goto out_put;
}

if (al.filtered)
goto out_put;

- /* Set thread to NULL to indicate addr_al is not initialized */
- addr_al.thread = NULL;
-
if (!show_event(sample, evsel, al.thread, &al, &addr_al))
goto out_put;

@@ -2238,7 +2247,8 @@ static int process_sample_event(struct perf_tool *tool,
}

out_put:
- addr_location__put(&al);
+ if (al.thread)
+ addr_location__put(&al);
return ret;
}

diff --git a/tools/perf/util/dlfilter.c b/tools/perf/util/dlfilter.c
index 03c4bf150656..e93c49c07999 100644
--- a/tools/perf/util/dlfilter.c
+++ b/tools/perf/util/dlfilter.c
@@ -175,6 +175,7 @@ static int dlfilter__open(struct dlfilter *d)
}
d->start = dlsym(d->handle, "start");
d->filter_event = dlsym(d->handle, "filter_event");
+ d->filter_event_early = dlsym(d->handle, "filter_event_early");
d->stop = dlsym(d->handle, "stop");
d->fns = dlsym(d->handle, "perf_dlfilter_fns");
if (d->fns)
@@ -251,7 +252,8 @@ int dlfilter__do_filter_event(struct dlfilter *d,
struct evsel *evsel,
struct machine *machine,
struct addr_location *al,
- struct addr_location *addr_al)
+ struct addr_location *addr_al,
+ bool early)
{
struct perf_dlfilter_sample d_sample;
struct perf_dlfilter_al d_ip_al;
@@ -322,7 +324,10 @@ int dlfilter__do_filter_event(struct dlfilter *d,

d->ctx_valid = true;

- ret = d->filter_event(d->data, &d_sample, d);
+ if (early)
+ ret = d->filter_event_early(d->data, &d_sample, d);
+ else
+ ret = d->filter_event(d->data, &d_sample, d);

d->ctx_valid = false;

diff --git a/tools/perf/util/dlfilter.h b/tools/perf/util/dlfilter.h
index 22b7636028dd..a994560e563d 100644
--- a/tools/perf/util/dlfilter.h
+++ b/tools/perf/util/dlfilter.h
@@ -40,6 +40,9 @@ struct dlfilter {
int (*filter_event)(void *data,
const struct perf_dlfilter_sample *sample,
void *ctx);
+ int (*filter_event_early)(void *data,
+ const struct perf_dlfilter_sample *sample,
+ void *ctx);

struct perf_dlfilter_fns *fns;
};
@@ -54,7 +57,8 @@ int dlfilter__do_filter_event(struct dlfilter *d,
struct evsel *evsel,
struct machine *machine,
struct addr_location *al,
- struct addr_location *addr_al);
+ struct addr_location *addr_al,
+ bool early);

void dlfilter__cleanup(struct dlfilter *d);

@@ -68,7 +72,20 @@ static inline int dlfilter__filter_event(struct dlfilter *d,
{
if (!d || !d->filter_event)
return 0;
- return dlfilter__do_filter_event(d, event, sample, evsel, machine, al, addr_al);
+ return dlfilter__do_filter_event(d, event, sample, evsel, machine, al, addr_al, false);
+}
+
+static inline int dlfilter__filter_event_early(struct dlfilter *d,
+ union perf_event *event,
+ struct perf_sample *sample,
+ struct evsel *evsel,
+ struct machine *machine,
+ struct addr_location *al,
+ struct addr_location *addr_al)
+{
+ if (!d || !d->filter_event_early)
+ return 0;
+ return dlfilter__do_filter_event(d, event, sample, evsel, machine, al, addr_al, true);
}

#endif
diff --git a/tools/perf/util/perf_dlfilter.h b/tools/perf/util/perf_dlfilter.h
index 82833ee8680d..f7a847fdee59 100644
--- a/tools/perf/util/perf_dlfilter.h
+++ b/tools/perf/util/perf_dlfilter.h
@@ -120,4 +120,10 @@ int stop(void *data, void *ctx);
*/
int filter_event(void *data, const struct perf_dlfilter_sample *sample, void *ctx);

+/*
+ * The same as 'filter_event' except it is called before internal
+ * filtering.
+ */
+int filter_event_early(void *data, const struct perf_dlfilter_sample *sample, void *ctx);
+
#endif
--
2.17.1