perf script: Add dlfilter__filter_event_early()

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>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210627131818.810-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 9 insertions, 4 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]
 ----