3 files changed, 49 insertions, 1 deletions

diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index cfea87c6f38e..5596129a71cf 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -266,6 +266,44 @@ Default is to monitor all CPUS.
         Record events of type PERF_RECORD_NAMESPACES and display it with the
         'cgroup_id' sort key.
 
+--switch-on EVENT_NAME::
+        Only consider events after this event is found.
+
+        E.g.:
+
+           Find out where broadcast packets are handled
+
+                perf probe -L icmp_rcv
+
+           Insert a probe there:
+
+                perf probe icmp_rcv:59
+
+           Start perf top and ask it to only consider the cycles events when a
+           broadcast packet arrives This will show a menu with two entries and
+           will start counting when a broadcast packet arrives:
+
+                perf top -e cycles,probe:icmp_rcv --switch-on=probe:icmp_rcv
+
+           Alternatively one can ask for --group and then two overhead columns
+           will appear, the first for cycles and the second for the switch-on event.
+
+                perf top --group -e cycles,probe:icmp_rcv --switch-on=probe:icmp_rcv
+
+        This may be interesting to measure a workload only after some initialization
+        phase is over, i.e. insert a perf probe at that point and use the above
+        examples replacing probe:icmp_rcv with the just-after-init probe.
+
+--switch-off EVENT_NAME::
+        Stop considering events after this event is found.
+
+--show-on-off-events::
+        Show the --switch-on/off events too. This has no effect in 'perf top' now
+        but probably we'll make the default not to show the switch-on/off events
+        on the --group mode and if there is only one event besides the off/on ones,
+        go straight to the histogram browser, just like 'perf top' with no events
+        explicitely specified does.
+
 
 INTERACTIVE PROMPTING KEYS
 --------------------------
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 78e7efc597a6..5970723cd55a 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1148,8 +1148,11 @@ static int deliver_event(struct ordered_events *qe,
         evsel = perf_evlist__id2evsel(session->evlist, sample.id);
         assert(evsel != NULL);
 
-        if (event->header.type == PERF_RECORD_SAMPLE)
+        if (event->header.type == PERF_RECORD_SAMPLE) {
+                if (evswitch__discard(&top->evswitch, evsel))
+                        return 0;
                 ++top->samples;
+        }
 
         switch (sample.cpumode) {
         case PERF_RECORD_MISC_USER:
@@ -1534,6 +1537,7 @@ int cmd_top(int argc, const char **argv)
                         "number of thread to run event synthesize"),
         OPT_BOOLEAN(0, "namespaces", &opts->record_namespaces,
                     "Record namespaces events"),
+        OPTS_EVSWITCH(&top.evswitch),
         OPT_END()
         };
         struct evlist *sb_evlist = NULL;
@@ -1567,6 +1571,10 @@ int cmd_top(int argc, const char **argv)
                 goto out_delete_evlist;
         }
 
+        status = evswitch__init(&top.evswitch, top.evlist, stderr);
+        if (status)
+                goto out_delete_evlist;
+
         if (symbol_conf.report_hierarchy) {
                 /* disable incompatible options */
                 symbol_conf.event_group = false;
diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index 2023e0bf6165..dc4bb6e52a83 100644
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -3,6 +3,7 @@
 #define __PERF_TOP_H 1
 
 #include "tool.h"
+#include "evswitch.h"
 #include "annotate.h"
 #include <linux/types.h>
 #include <stddef.h>
@@ -18,6 +19,7 @@ struct perf_top {
         struct evlist *evlist;
         struct record_opts record_opts;
         struct annotation_options annotation_opts;
+        struct evswitch    evswitch;
         /*
          * Symbols will be added here in perf_event__process_sample and will
          * get out after decayed.