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>

5 files changed, 136 insertions, 75 deletions

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 0ee868e6f63b..6284ed2317f2 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -2,6 +2,7 @@
 #include "perf.h"
 
 #include "util/util.h"
+#include "util/evlist.h"
 #include "util/cache.h"
 #include "util/evsel.h"
 #include "util/symbol.h"
@@ -1358,12 +1359,13 @@ static void sort_lat(void)
 static struct trace_sched_handler *trace_handler;
 
 static void
-process_sched_wakeup_event(void *data, struct machine *machine,
+process_sched_wakeup_event(struct perf_tool *tool __used,
                            struct event *event,
-                           int cpu __used,
-                           u64 timestamp __used,
-                           struct thread *thread __used)
+                           struct perf_sample *sample,
+                           struct machine *machine,
+                           struct thread *thread)
 {
+        void *data = sample->raw_data;
         struct trace_wakeup_event wakeup_event;
 
         FILL_COMMON_FIELDS(wakeup_event, event, data);
@@ -1376,7 +1378,7 @@ process_sched_wakeup_event(void *data, struct machine *machine,
 
         if (trace_handler->wakeup_event)
                 trace_handler->wakeup_event(&wakeup_event, machine, event,
-                                            cpu, timestamp, thread);
+                                            sample->cpu, sample->time, thread);
 }
 
 /*
@@ -1471,14 +1473,15 @@ map_switch_event(struct trace_switch_event *switch_event,
         }
 }
 
-
 static void
-process_sched_switch_event(void *data, struct machine *machine,
+process_sched_switch_event(struct perf_tool *tool __used,
                            struct event *event,
-                           int this_cpu,
-                           u64 timestamp __used,
-                           struct thread *thread __used)
+                           struct perf_sample *sample,
+                           struct machine *machine,
+                           struct thread *thread)
 {
+        int this_cpu = sample->cpu;
+        void *data = sample->raw_data;
         struct trace_switch_event switch_event;
 
         FILL_COMMON_FIELDS(switch_event, event, data);
@@ -1501,18 +1504,19 @@ process_sched_switch_event(void *data, struct machine *machine,
         }
         if (trace_handler->switch_event)
                 trace_handler->switch_event(&switch_event, machine, event,
-                                            this_cpu, timestamp, thread);
+                                            this_cpu, sample->time, thread);
 
         curr_pid[this_cpu] = switch_event.next_pid;
 }
 
 static void
-process_sched_runtime_event(void *data, struct machine *machine,
-                           struct event *event,
-                           int cpu __used,
-                           u64 timestamp __used,
-                           struct thread *thread __used)
+process_sched_runtime_event(struct perf_tool *tool __used,
+                            struct event *event,
+                            struct perf_sample *sample,
+                            struct machine *machine,
+                            struct thread *thread)
 {
+        void *data = sample->raw_data;
         struct trace_runtime_event runtime_event;
 
         FILL_ARRAY(runtime_event, comm, event, data);
@@ -1521,16 +1525,18 @@ process_sched_runtime_event(void *data, struct machine *machine,
         FILL_FIELD(runtime_event, vruntime, event, data);
 
         if (trace_handler->runtime_event)
-                trace_handler->runtime_event(&runtime_event, machine, event, cpu, timestamp, thread);
+                trace_handler->runtime_event(&runtime_event, machine, event,
+                                             sample->cpu, sample->time, thread);
 }
 
 static void
-process_sched_fork_event(void *data,
+process_sched_fork_event(struct perf_tool *tool __used,
                          struct event *event,
-                         int cpu __used,
-                         u64 timestamp __used,
-                         struct thread *thread __used)
+                         struct perf_sample *sample,
+                         struct machine *machine __used,
+                         struct thread *thread)
 {
+        void *data = sample->raw_data;
         struct trace_fork_event fork_event;
 
         FILL_COMMON_FIELDS(fork_event, event, data);
@@ -1542,13 +1548,14 @@ process_sched_fork_event(void *data,
 
         if (trace_handler->fork_event)
                 trace_handler->fork_event(&fork_event, event,
-                                          cpu, timestamp, thread);
+                                          sample->cpu, sample->time, thread);
 }
 
 static void
-process_sched_exit_event(struct event *event,
-                         int cpu __used,
-                         u64 timestamp __used,
+process_sched_exit_event(struct perf_tool *tool __used,
+                         struct event *event,
+                         struct perf_sample *sample __used,
+                         struct machine *machine __used,
                          struct thread *thread __used)
 {
         if (verbose)
@@ -1556,12 +1563,13 @@ process_sched_exit_event(struct event *event,
 }
 
 static void
-process_sched_migrate_task_event(void *data, struct machine *machine,
-                           struct event *event,
-                           int cpu __used,
-                           u64 timestamp __used,
-                           struct thread *thread __used)
+process_sched_migrate_task_event(struct perf_tool *tool __used,
+                                 struct event *event,
+                                 struct perf_sample *sample,
+                                 struct machine *machine,
+                                 struct thread *thread)
 {
+        void *data = sample->raw_data;
         struct trace_migrate_task_event migrate_task_event;
 
         FILL_COMMON_FIELDS(migrate_task_event, event, data);
@@ -1573,67 +1581,46 @@ process_sched_migrate_task_event(void *data, struct machine *machine,
 
         if (trace_handler->migrate_task_event)
                 trace_handler->migrate_task_event(&migrate_task_event, machine,
-                                                 event, cpu, timestamp, thread);
+                                                  event, sample->cpu,
+                                                  sample->time, thread);
 }
 
-static void process_raw_event(union perf_event *raw_event __used,
-                              struct machine *machine, void *data, int cpu,
-                              u64 timestamp, struct thread *thread)
-{
-        struct event *event;
-        int type;
-
-
-        type = trace_parse_common_type(data);
-        event = trace_find_event(type);
-
-        if (!strcmp(event->name, "sched_switch"))
-                process_sched_switch_event(data, machine, event, cpu, timestamp, thread);
-        if (!strcmp(event->name, "sched_stat_runtime"))
-                process_sched_runtime_event(data, machine, event, cpu, timestamp, thread);
-        if (!strcmp(event->name, "sched_wakeup"))
-                process_sched_wakeup_event(data, machine, event, cpu, timestamp, thread);
-        if (!strcmp(event->name, "sched_wakeup_new"))
-                process_sched_wakeup_event(data, machine, event, cpu, timestamp, thread);
-        if (!strcmp(event->name, "sched_process_fork"))
-                process_sched_fork_event(data, event, cpu, timestamp, thread);
-        if (!strcmp(event->name, "sched_process_exit"))
-                process_sched_exit_event(event, cpu, timestamp, thread);
-        if (!strcmp(event->name, "sched_migrate_task"))
-                process_sched_migrate_task_event(data, machine, event, cpu, timestamp, thread);
-}
+typedef void (*tracepoint_handler)(struct perf_tool *tool, struct event *event,
+                                   struct perf_sample *sample,
+                                   struct machine *machine,
+                                   struct thread *thread);
 
-static int process_sample_event(struct perf_tool *tool __used,
-                                union perf_event *event,
-                                struct perf_sample *sample,
-                                struct perf_evsel *evsel,
-                                struct machine *machine)
+static int perf_sched__process_tracepoint_sample(struct perf_tool *tool,
+                                                 union perf_event *event __used,
+                                                 struct perf_sample *sample,
+                                                 struct perf_evsel *evsel,
+                                                 struct machine *machine)
 {
-        struct thread *thread;
-
-        if (!(evsel->attr.sample_type & PERF_SAMPLE_RAW))
-                return 0;
+        struct thread *thread = machine__findnew_thread(machine, sample->pid);
 
-        thread = machine__findnew_thread(machine, sample->pid);
         if (thread == NULL) {
-                pr_debug("problem processing %d event, skipping it.\n",
-                         event->header.type);
+                pr_debug("problem processing %s event, skipping it.\n",
+                         evsel->name);
                 return -1;
         }
 
-        dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+        evsel->hists.stats.total_period += sample->period;
+        hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
 
-        if (profile_cpu != -1 && profile_cpu != (int)sample->cpu)
-                return 0;
+        if (evsel->handler.func != NULL) {
+                tracepoint_handler f = evsel->handler.func;
 
-        process_raw_event(event, machine, sample->raw_data, sample->cpu,
-                          sample->time, thread);
+                if (evsel->handler.data == NULL)
+                        evsel->handler.data = trace_find_event(evsel->attr.config);
+
+                f(tool, evsel->handler.data, sample, machine, thread);
+        }
 
         return 0;
 }
 
 static struct perf_tool perf_sched = {
-        .sample                 = process_sample_event,
+        .sample                 = perf_sched__process_tracepoint_sample,
         .comm                   = perf_event__process_comm,
         .lost                   = perf_event__process_lost,
         .fork                   = perf_event__process_task,
@@ -1643,11 +1630,23 @@ static struct perf_tool perf_sched = {
 static void read_events(bool destroy, struct perf_session **psession)
 {
         int err = -EINVAL;
+        const struct perf_evsel_str_handler handlers[] = {
+                { "sched:sched_switch",       process_sched_switch_event, },
+                { "sched:sched_stat_runtime", process_sched_runtime_event, },
+                { "sched:sched_wakeup",       process_sched_wakeup_event, },
+                { "sched:sched_wakeup_new",   process_sched_wakeup_event, },
+                { "sched:sched_process_fork", process_sched_fork_event, },
+                { "sched:sched_process_exit", process_sched_exit_event, },
+                { "sched:sched_migrate_task", process_sched_migrate_task_event, },
+        };
         struct perf_session *session = perf_session__new(input_name, O_RDONLY,
                                                          0, false, &perf_sched);
         if (session == NULL)
                 die("No Memory");
 
+        err = perf_evlist__set_tracepoints_handlers_array(session->evlist, handlers);
+        assert(err == 0);
+
         if (perf_session__has_traces(session, "record -R")) {
                 err = perf_session__process_events(session, &perf_sched);
                 if (err)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index d44e3df13a8f..b36f26fe767a 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -207,6 +207,48 @@ out_free_attrs:
         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 2202e7b04103..f94ed7e0d987 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -36,6 +36,11 @@ struct perf_evlist {
         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 @@ int perf_evlist__add_attrs(struct perf_evlist *evlist,
                            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 @@ int perf_evlist__add_tracepoints(struct perf_evlist *evlist,
 #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 6421c07f5015..326b8e4d5035 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -61,6 +61,10 @@ struct perf_evsel {
                 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 89ff1b551a74..b0e1aadba8d5 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;