[PATCH RFC V8 1/4] perf,tools: per-event time support
From: Kan Liang
Date: Tue Aug 04 2015 - 11:46:28 EST
From: Kan Liang <kan.liang@xxxxxxxxx>
This patchkit adds the ability to turn off time stamps per event.
One usable case of partial time is to work with per-event callgraph to
enable "PEBS threshold > 1" (https://lkml.org/lkml/2015/5/10/196), which
can significantly reduce the sampling overhead.
The event samples with time stamps off will not be ordered.
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
---
tools/perf/Documentation/perf-record.txt | 4 +++-
tools/perf/util/evsel.c | 14 +++++++++++---
tools/perf/util/evsel.h | 2 ++
tools/perf/util/parse-events.c | 12 ++++++++++++
tools/perf/util/parse-events.h | 1 +
tools/perf/util/parse-events.l | 1 +
tools/perf/util/pmu.c | 2 +-
7 files changed, 31 insertions(+), 5 deletions(-)
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index ac41350..0d852d1 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -49,7 +49,9 @@ OPTIONS
These params can be used to overload default config values per event.
Here is a list of the params.
- 'period': Set event sampling period
-
+ - 'time': Disable/enable time stamping. Acceptable values are 1 for
+ enabling time stamping. 0 for disabling time stamping.
+ The default is 1.
Note: If user explicitly sets options which conflict with the params,
the value set by the params will be overridden.
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 7d3acba..7febfe2 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -587,15 +587,23 @@ perf_evsel__config_callgraph(struct perf_evsel *evsel,
}
}
-static void apply_config_terms(struct perf_event_attr *attr __maybe_unused,
- struct list_head *config_terms)
+static void apply_config_terms(struct perf_evsel *evsel)
{
struct perf_evsel_config_term *term;
+ struct list_head *config_terms = &evsel->config_terms;
+ struct perf_event_attr *attr = &evsel->attr;
list_for_each_entry(term, config_terms, list) {
switch (term->type) {
case PERF_EVSEL__CONFIG_TERM_PERIOD:
attr->sample_period = term->val.period;
+ break;
+ case PERF_EVSEL__CONFIG_TERM_TIME:
+ if (term->val.time)
+ perf_evsel__set_sample_bit(evsel, TIME);
+ else
+ perf_evsel__reset_sample_bit(evsel, TIME);
+ break;
default:
break;
}
@@ -798,7 +806,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
* Apply event specific term settings,
* it overloads any global configuration.
*/
- apply_config_terms(attr, &evsel->config_terms);
+ apply_config_terms(evsel);
}
static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index a7d2175..6a12908 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -39,6 +39,7 @@ struct cgroup_sel;
*/
enum {
PERF_EVSEL__CONFIG_TERM_PERIOD,
+ PERF_EVSEL__CONFIG_TERM_TIME,
PERF_EVSEL__CONFIG_TERM_MAX,
};
@@ -47,6 +48,7 @@ struct perf_evsel_config_term {
int type;
union {
u64 period;
+ bool time;
} val;
};
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 09bee93..a6cb9af 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -603,6 +603,14 @@ do { \
* attr->branch_sample_type = term->val.num;
*/
break;
+ case PARSE_EVENTS__TERM_TYPE_TIME:
+ CHECK_TYPE_VAL(NUM);
+ if (term->val.num > 1) {
+ err->str = strdup("expected 0 or 1");
+ err->idx = term->err_val;
+ return -EINVAL;
+ }
+ break;
case PARSE_EVENTS__TERM_TYPE_NAME:
CHECK_TYPE_VAL(STR);
break;
@@ -650,6 +658,10 @@ do { \
switch (term->type_term) {
case PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD:
ADD_CONFIG_TERM(PERIOD, period, term->val.num);
+ break;
+ case PARSE_EVENTS__TERM_TYPE_TIME:
+ ADD_CONFIG_TERM(TIME, time, term->val.num);
+ break;
default:
break;
}
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 2063048..e6f9aacc 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -63,6 +63,7 @@ enum {
PARSE_EVENTS__TERM_TYPE_NAME,
PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD,
PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE,
+ PARSE_EVENTS__TERM_TYPE_TIME,
};
struct parse_events_term {
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 13cef3c..f542750 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -183,6 +183,7 @@ config2 { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG2); }
name { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_NAME); }
period { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD); }
branch_type { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE); }
+time { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_TIME); }
, { return ','; }
"/" { BEGIN(INITIAL); return '/'; }
{name_minus} { return str(yyscanner, PE_NAME); }
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 7bcb8c3..b615cdf 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -607,7 +607,7 @@ static char *formats_error_string(struct list_head *formats)
{
struct perf_pmu_format *format;
char *err, *str;
- static const char *static_terms = "config,config1,config2,name,period,branch_type\n";
+ static const char *static_terms = "config,config1,config2,name,period,branch_type,time\n";
unsigned i = 0;
if (!asprintf(&str, "valid terms:"))
--
1.8.3.1
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