perf tools: Save some loops using perf_evlist__id2evsel
Since we already ask for PERF_SAMPLE_ID and use it to quickly find the
associated evsel, add handler func + data to struct perf_evsel to avoid
using chains of if(strcmp(event_name)) and also to avoid all the linear
list searches via trace_event_find.
To demonstrate the technique convert 'perf sched' to it:
# perf sched record sleep 5m
And then:
Performance counter stats for '/tmp/oldperf sched lat':
646.929438 task-clock # 0.999 CPUs utilized
9 context-switches # 0.000 M/sec
0 CPU-migrations # 0.000 M/sec
20,901 page-faults # 0.032 M/sec
1,290,144,450 cycles # 1.994 GHz
<not supported> stalled-cycles-frontend
<not supported> stalled-cycles-backend
1,606,158,439 instructions # 1.24 insns per cycle
339,088,395 branches # 524.151 M/sec
4,550,735 branch-misses # 1.34% of all branches
0.647524759 seconds time elapsed
Versus:
Performance counter stats for 'perf sched lat':
473.564691 task-clock # 0.999 CPUs utilized
9 context-switches # 0.000 M/sec
0 CPU-migrations # 0.000 M/sec
20,903 page-faults # 0.044 M/sec
944,367,984 cycles # 1.994 GHz
<not supported> stalled-cycles-frontend
<not supported> stalled-cycles-backend
1,442,385,571 instructions # 1.53 insns per cycle
308,383,106 branches # 651.195 M/sec
4,481,784 branch-misses # 1.45% of all branches
0.474215751 seconds time elapsed
[root@emilia ~]#
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-1kbzpl74lwi6lavpqke2u2p3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index d44e3df..b36f26f 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -207,6 +207,48 @@
return err;
}
+static struct perf_evsel *
+ perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
+{
+ struct perf_evsel *evsel;
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ if (evsel->attr.type == PERF_TYPE_TRACEPOINT &&
+ (int)evsel->attr.config == id)
+ return evsel;
+ }
+
+ return NULL;
+}
+
+int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist,
+ const struct perf_evsel_str_handler *assocs,
+ size_t nr_assocs)
+{
+ struct perf_evsel *evsel;
+ int err;
+ size_t i;
+
+ for (i = 0; i < nr_assocs; i++) {
+ err = trace_event__id(assocs[i].name);
+ if (err < 0)
+ goto out;
+
+ evsel = perf_evlist__find_tracepoint_by_id(evlist, err);
+ if (evsel == NULL)
+ continue;
+
+ err = -EEXIST;
+ if (evsel->handler.func != NULL)
+ goto out;
+ evsel->handler.func = assocs[i].handler;
+ }
+
+ err = 0;
+out:
+ return err;
+}
+
void perf_evlist__disable(struct perf_evlist *evlist)
{
int cpu, thread;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 2202e7b..f94ed7e 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -36,6 +36,11 @@
struct perf_evsel *selected;
};
+struct perf_evsel_str_handler {
+ const char *name;
+ void *handler;
+};
+
struct perf_evsel;
struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
@@ -51,6 +56,9 @@
struct perf_event_attr *attrs, size_t nr_attrs);
int perf_evlist__add_tracepoints(struct perf_evlist *evlist,
const char *tracepoints[], size_t nr_tracepoints);
+int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist,
+ const struct perf_evsel_str_handler *assocs,
+ size_t nr_assocs);
#define perf_evlist__add_attrs_array(evlist, array) \
perf_evlist__add_attrs(evlist, array, ARRAY_SIZE(array))
@@ -58,6 +66,9 @@
#define perf_evlist__add_tracepoints_array(evlist, array) \
perf_evlist__add_tracepoints(evlist, array, ARRAY_SIZE(array))
+#define perf_evlist__set_tracepoints_handlers_array(evlist, array) \
+ perf_evlist__set_tracepoints_handlers(evlist, array, ARRAY_SIZE(array))
+
void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
int cpu, int thread, u64 id);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 6421c07..326b8e4 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -61,6 +61,10 @@
off_t id_offset;
};
struct cgroup_sel *cgrp;
+ struct {
+ void *func;
+ void *data;
+ } handler;
bool supported;
};
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index 89ff1b5..b0e1aad 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -1,8 +1,13 @@
#ifndef __PERF_TOOL_H
#define __PERF_TOOL_H
+#include <stdbool.h>
+
struct perf_session;
+union perf_event;
+struct perf_evlist;
struct perf_evsel;
+struct perf_sample;
struct perf_tool;
struct machine;