diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index 79476c906b1ae28405310a286774c350c93a2c19..0ea59d45aef105f6eab311b9cc89f37f398b967a 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -1873,31 +1873,45 @@ The available handlers are:
The available actions are:
- - <synthetic_event_name>(param list) - generate synthetic event
+ - trace(<synthetic_event_name>,param list) - generate synthetic event
- save(field,...) - save current event fields
- snapshot() - snapshot the trace buffer
The following commonly-used handler.action pairs are available:
- - onmatch(matching.event).<synthetic_event_name>(param list)
+ - onmatch(matching.event).trace(<synthetic_event_name>,param list)
- The 'onmatch(matching.event).<synthetic_event_name>(params)' hist
- trigger action is invoked whenever an event matches and the
- histogram entry would be added or updated. It causes the named
- synthetic event to be generated with the values given in the
+ The 'onmatch(matching.event).trace(<synthetic_event_name>,param
+ list)' hist trigger action is invoked whenever an event matches
+ and the histogram entry would be added or updated. It causes the
+ named synthetic event to be generated with the values given in the
'param list'. The result is the generation of a synthetic event
that consists of the values contained in those variables at the
- time the invoking event was hit.
-
- The 'param list' consists of one or more parameters which may be
- either variables or fields defined on either the 'matching.event'
- or the target event. The variables or fields specified in the
- param list may be either fully-qualified or unqualified. If a
- variable is specified as unqualified, it must be unique between
- the two events. A field name used as a param can be unqualified
- if it refers to the target event, but must be fully qualified if
- it refers to the matching event. A fully-qualified name is of the
- form 'system.event_name.$var_name' or 'system.event_name.field'.
+ time the invoking event was hit. For example, if the synthetic
+ event name is 'wakeup_latency', a wakeup_latency event is
+ generated using onmatch(event).trace(wakeup_latency,arg1,arg2).
+
+ There is also an equivalent alternative form available for
+ generating synthetic events. In this form, the synthetic event
+ name is used as if it were a function name. For example, using
+ the 'wakeup_latency' synthetic event name again, the
+ wakeup_latency event would be generated by invoking it as if it
+ were a function call, with the event field values passed in as
+ arguments: onmatch(event).wakeup_latency(arg1,arg2). The syntax
+ for this form is:
+
+ onmatch(matching.event).<synthetic_event_name>(param list)
+
+ In either case, the 'param list' consists of one or more
+ parameters which may be either variables or fields defined on
+ either the 'matching.event' or the target event. The variables or
+ fields specified in the param list may be either fully-qualified
+ or unqualified. If a variable is specified as unqualified, it
+ must be unique between the two events. A field name used as a
+ param can be unqualified if it refers to the target event, but
+ must be fully qualified if it refers to the matching event. A
+ fully-qualified name is of the form 'system.event_name.$var_name'
+ or 'system.event_name.field'.
The 'matching.event' specification is simply the fully qualified
event name of the event that matches the target event for the
@@ -1928,6 +1942,12 @@ The following commonly-used handler.action pairs are available:
wakeup_new_test($testpid) if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
+ Or, equivalently, using the 'trace' keyword syntax:
+
+ # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\
+ trace(wakeup_new_test,$testpid) if comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
+
Creating and displaying a histogram based on those events is now
just a matter of using the fields and new synthetic event in the
tracing/events/synthetic directory, as usual::
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index be6779f963c6c448834594ca4f036ef46d364c6a..0460cc0f28fd2e47e080d43be88de3303abecc30 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4918,7 +4918,7 @@ static const char readme_msg[] =
"\t onmax(var) - invoke if var exceeds current max\n"
"\t onchange(var) - invoke action if var changes\n\n"
"\t The available actions are:\n\n"
- "\t <synthetic_event>(param list) - generate synthetic event\n"
+ "\t trace(<synthetic_event>,param list) - generate synthetic event\n"
"\t save(field,...) - save current event fields\n"
#ifdef CONFIG_TRACER_SNAPSHOT
"\t snapshot() - snapshot the trace buffer\n"
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 2f3323ca9d24e18eefa6cfab914e070c16e6aba3..66386ba1425f323af82d7e0fe5d3aedd3b4136bd 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -419,6 +419,8 @@ struct action_data {
*/
unsigned int var_ref_idx;
struct synth_event *synth_event;
+ bool use_trace_keyword;
+ char *synth_event_name;
union {
struct {
@@ -3700,6 +3702,8 @@ static void action_data_destroy(struct action_data *data)
if (data->synth_event)
data->synth_event->ref--;
+ kfree(data->synth_event_name);
+
kfree(data);
}
@@ -3781,6 +3785,7 @@ static int track_data_create(struct hist_trigger_data *hist_data,
static int parse_action_params(char *params, struct action_data *data)
{
char *param, *saved_param;
+ bool first_param = true;
int ret = 0;
while (params) {
@@ -3809,6 +3814,13 @@ static int parse_action_params(char *params, struct action_data *data)
goto out;
}
+ if (first_param && data->use_trace_keyword) {
+ data->synth_event_name = saved_param;
+ first_param = false;
+ continue;
+ }
+ first_param = false;
+
data->params[data->n_params++] = saved_param;
}
out:
@@ -3886,6 +3898,9 @@ static int action_parse(char *str, struct action_data *data,
} else {
char *params = strsep(&str, ")");
+ if (str_has_prefix(action_name, "trace"))
+ data->use_trace_keyword = true;
+
if (params) {
ret = parse_action_params(params, data);
if (ret)
@@ -4088,13 +4103,19 @@ static int trace_action_create(struct hist_trigger_data *hist_data,
unsigned int i, var_ref_idx;
unsigned int field_pos = 0;
struct synth_event *event;
+ char *synth_event_name;
int ret = 0;
lockdep_assert_held(&event_mutex);
- event = find_synth_event(data->action_name);
+ if (data->use_trace_keyword)
+ synth_event_name = data->synth_event_name;
+ else
+ synth_event_name = data->action_name;
+
+ event = find_synth_event(synth_event_name);
if (!event) {
- hist_err("trace action: Couldn't find synthetic event: ", data->action_name);
+ hist_err("trace action: Couldn't find synthetic event: ", synth_event_name);
return -EINVAL;
}
@@ -4841,8 +4862,10 @@ static void print_action_spec(struct seq_file *m,
seq_puts(m, ",");
}
} else if (data->action == ACTION_TRACE) {
+ if (data->use_trace_keyword)
+ seq_printf(m, "%s", data->synth_event_name);
for (i = 0; i < data->n_params; i++) {
- if (i)
+ if (i || data->use_trace_keyword)
seq_puts(m, ",");
seq_printf(m, "%s", data->params[i]);
}
@@ -4890,6 +4913,7 @@ static bool actions_match(struct hist_trigger_data *hist_data,
for (i = 0; i < hist_data->n_actions; i++) {
struct action_data *data = hist_data->actions[i];
struct action_data *data_test = hist_data_test->actions[i];
+ char *action_name, *action_name_test;
if (data->handler != data_test->handler)
return false;
@@ -4904,7 +4928,17 @@ static bool actions_match(struct hist_trigger_data *hist_data,
return false;
}
- if (strcmp(data->action_name, data_test->action_name) != 0)
+ if (data->use_trace_keyword)
+ action_name = data->synth_event_name;
+ else
+ action_name = data->action_name;
+
+ if (data_test->use_trace_keyword)
+ action_name_test = data_test->synth_event_name;
+ else
+ action_name_test = data_test->action_name;
+
+ if (strcmp(action_name, action_name_test) != 0)
return false;
if (data->handler == HANDLER_ONMATCH) {