perf report: Add --num-thread option to control number of thread
The --num-thread is to control number of thread to process events when
--multi-thread option is enabled. Default value is the number of cpu
on the system that runs perf report. The config variable
'report.num-thread' is also added to set a different default value.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 3917710e..c605049 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -356,6 +356,11 @@
--multi-thread::
Speed up report by parallelizing sample processing using multi-thread.
+--num-thread::
+ Number of thread to process sample events. Should be greater than or
+ equals to 2. Default is number of cpus on the system unless
+ report.num-thread config variable is set.
+
include::callchain-overhead-calculation.txt[]
SEE ALSO
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 4d08e5f..71ab710 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -54,6 +54,7 @@
bool header;
bool header_only;
bool multi_thread;
+ int nr_thread;
int max_stack;
struct perf_read_values show_threads_values;
const char *pretty_printing_style;
@@ -89,6 +90,10 @@
rep->multi_thread = perf_config_bool(var, value);
return 0;
}
+ if (!strcmp(var, "report.num-thread")) {
+ rep->nr_thread = perf_config_int(var, value);
+ return 0;
+ }
return perf_default_config(var, value, cb);
}
@@ -522,7 +527,8 @@
if (rep->multi_thread) {
rep->tool.sample = process_sample_event_mt;
- ret = perf_session__process_events_mt(session, rep);
+ ret = perf_session__process_events_mt(session, rep->nr_thread,
+ rep);
} else {
ret = perf_session__process_events(session);
}
@@ -664,6 +670,7 @@
},
.max_stack = PERF_MAX_STACK_DEPTH,
.pretty_printing_style = "normal",
+ .nr_thread = -1,
};
const struct option options[] = {
OPT_STRING('i', "input", &input_name, "file",
@@ -774,6 +781,8 @@
itrace_parse_synth_opts),
OPT_BOOLEAN(0, "multi-thread", &report.multi_thread,
"Speed up sample processing using multi-thead"),
+ OPT_INTEGER(0, "num-thread", &report.nr_thread,
+ "Number of thread to process samples (>= 2)"),
OPT_END()
};
struct perf_data_file file = {
@@ -820,9 +829,21 @@
session->itrace_synth_opts = &itrace_synth_opts;
- if (report.multi_thread && !perf_has_index) {
- pr_debug("fallback to single thread for normal data file.\n");
- report.multi_thread = false;
+ if (report.multi_thread) {
+ if (!perf_has_index) {
+ pr_debug("fallback to single thread for normal data file.\n");
+ report.multi_thread = false;
+ } else {
+ if (report.nr_thread == -1)
+ report.nr_thread = sysconf(_SC_NPROCESSORS_ONLN);
+ else if (report.nr_thread < 2) {
+ pr_err("invalid number of thread: %d\n",
+ report.nr_thread);
+ parse_options_usage(report_usage, options,
+ "num-thread", 0);
+ goto error;
+ }
+ }
}
report.session = session;
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 5f6c319..747d638 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1726,7 +1726,8 @@
return arg;
}
-int perf_session__process_events_mt(struct perf_session *session, void *arg)
+int perf_session__process_events_mt(struct perf_session *session,
+ int nr_thread, void *arg)
{
struct perf_data_file *file = session->file;
struct perf_evlist *evlist = session->evlist;
@@ -1742,7 +1743,6 @@
int err, i, k;
int nr_index = session->header.nr_index;
u64 size = perf_data_file__size(file);
- int nr_thread = sysconf(_SC_NPROCESSORS_ONLN);
if (perf_data_file__is_pipe(file) || !session->header.index) {
pr_err("data file doesn't contain the index table\n");
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index fde658d..a033e10 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -56,7 +56,8 @@
struct perf_sample *sample);
int perf_session__process_events(struct perf_session *session);
-int perf_session__process_events_mt(struct perf_session *session, void *arg);
+int perf_session__process_events_mt(struct perf_session *session,
+ int nr_thread, void *arg);
int perf_session__queue_event(struct perf_session *s, union perf_event *event,
struct perf_sample *sample, u64 file_offset);
