perf tools: Refactor all_tids to hold nr and the map

So that later, we can pass the thread_map instance instead of
(thread_num, thread_map) for things like perf_evsel__open and friends,
just like was done with cpu_map.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

5 files changed, 88 insertions, 85 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 220e6e7f0b97..7bc049035484 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -54,8 +54,7 @@ static bool			sample_id_all_avail		=   true;
 static bool                     system_wide                     =  false;
 static pid_t                    target_pid                      =     -1;
 static pid_t                    target_tid                      =     -1;
-static pid_t                    *all_tids                       =      NULL;
-static int                      thread_num                      =      0;
+static struct thread_map        *threads;
 static pid_t                    child_pid                       =     -1;
 static bool                     no_inherit                      =  false;
 static enum write_mode_t        write_mode                      = WRITE_FORCE;
@@ -318,9 +317,9 @@ static void create_counter(struct perf_evsel *evsel, int cpu)
 retry_sample_id:
         attr->sample_id_all = sample_id_all_avail ? 1 : 0;
 
-        for (thread_index = 0; thread_index < thread_num; thread_index++) {
+        for (thread_index = 0; thread_index < threads->nr; thread_index++) {
 try_again:
-                FD(evsel, nr_cpu, thread_index) = sys_perf_event_open(attr, all_tids[thread_index], cpu, group_fd, 0);
+                FD(evsel, nr_cpu, thread_index) = sys_perf_event_open(attr, threads->map[thread_index], cpu, group_fd, 0);
 
                 if (FD(evsel, nr_cpu, thread_index) < 0) {
                         int err = errno;
@@ -653,7 +652,7 @@ static int __cmd_record(int argc, const char **argv)
                 }
 
                 if (!system_wide && target_tid == -1 && target_pid == -1)
-                        all_tids[0] = child_pid;
+                        threads->map[0] = child_pid;
 
                 close(child_ready_pipe[1]);
                 close(go_pipe[0]);
@@ -793,7 +792,7 @@ static int __cmd_record(int argc, const char **argv)
 
                                 list_for_each_entry(pos, &evsel_list, node) {
                                         for (thread = 0;
-                                                thread < thread_num;
+                                                thread < threads->nr;
                                                 thread++)
                                                 ioctl(FD(pos, i, thread),
                                                         PERF_EVENT_IOC_DISABLE);
@@ -910,21 +909,13 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
                 goto out_symbol_exit;
         }
 
-        if (target_pid != -1) {
+        if (target_pid != -1)
                 target_tid = target_pid;
-                thread_num = find_all_tid(target_pid, &all_tids);
-                if (thread_num <= 0) {
-                        fprintf(stderr, "Can't find all threads of pid %d\n",
-                                        target_pid);
-                        usage_with_options(record_usage, record_options);
-                }
-        } else {
-                all_tids=malloc(sizeof(pid_t));
-                if (!all_tids)
-                        goto out_symbol_exit;
 
-                all_tids[0] = target_tid;
-                thread_num = 1;
+        threads = thread_map__new(target_pid, target_tid);
+        if (threads == NULL) {
+                pr_err("Problems finding threads of monitor\n");
+                usage_with_options(record_usage, record_options);
         }
 
         cpus = cpu_map__new(cpu_list);
@@ -934,11 +925,11 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
         }
 
         list_for_each_entry(pos, &evsel_list, node) {
-                if (perf_evsel__alloc_fd(pos, cpus->nr, thread_num) < 0)
+                if (perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
                         goto out_free_fd;
         }
-        event_array = malloc(
-                sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
+        event_array = malloc((sizeof(struct pollfd) * MAX_NR_CPUS *
+                              MAX_COUNTERS * threads->nr));
         if (!event_array)
                 goto out_free_fd;
 
@@ -965,8 +956,8 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 out_free_event_array:
         free(event_array);
 out_free_fd:
-        free(all_tids);
-        all_tids = NULL;
+        thread_map__delete(threads);
+        threads = NULL;
 out_symbol_exit:
         symbol__exit();
         return err;
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 3f4a431fb5a4..6b9146cd1ea9 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -81,8 +81,7 @@ static bool			scale				=  true;
 static bool                     no_aggr                         = false;
 static pid_t                    target_pid                      = -1;
 static pid_t                    target_tid                      = -1;
-static pid_t                    *all_tids                       =  NULL;
-static int                      thread_num                      =  0;
+static struct thread_map        *threads;
 static pid_t                    child_pid                       = -1;
 static bool                     null_run                        =  false;
 static bool                     big_num                         =  true;
@@ -175,7 +174,7 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
                 attr->enable_on_exec = 1;
         }
 
-        return perf_evsel__open_per_thread(evsel, thread_num, all_tids);
+        return perf_evsel__open_per_thread(evsel, threads->nr, threads->map);
 }
 
 /*
@@ -200,7 +199,7 @@ static int read_counter_aggr(struct perf_evsel *counter)
         u64 *count = counter->counts->aggr.values;
         int i;
 
-        if (__perf_evsel__read(counter, cpus->nr, thread_num, scale) < 0)
+        if (__perf_evsel__read(counter, cpus->nr, threads->nr, scale) < 0)
                 return -1;
 
         for (i = 0; i < 3; i++)
@@ -298,7 +297,7 @@ static int run_perf_stat(int argc __used, const char **argv)
                 }
 
                 if (target_tid == -1 && target_pid == -1 && !system_wide)
-                        all_tids[0] = child_pid;
+                        threads->map[0] = child_pid;
 
                 /*
                  * Wait for the child to be ready to exec.
@@ -353,7 +352,7 @@ static int run_perf_stat(int argc __used, const char **argv)
         } else {
                 list_for_each_entry(counter, &evsel_list, node) {
                         read_counter_aggr(counter);
-                        perf_evsel__close_fd(counter, cpus->nr, thread_num);
+                        perf_evsel__close_fd(counter, cpus->nr, threads->nr);
                 }
         }
 
@@ -693,6 +692,15 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
                 }
         }
 
+        if (target_pid != -1)
+                target_tid = target_pid;
+
+        threads = thread_map__new(target_pid, target_tid);
+        if (threads == NULL) {
+                pr_err("Problems finding threads of monitor\n");
+                usage_with_options(stat_usage, options);
+        }
+
         if (system_wide)
                 cpus = cpu_map__new(cpu_list);
         else
@@ -704,27 +712,10 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
                 return -1;
         }
 
-        if (target_pid != -1) {
-                target_tid = target_pid;
-                thread_num = find_all_tid(target_pid, &all_tids);
-                if (thread_num <= 0) {
-                        fprintf(stderr, "Can't find all threads of pid %d\n",
-                                        target_pid);
-                        usage_with_options(stat_usage, options);
-                }
-        } else {
-                all_tids=malloc(sizeof(pid_t));
-                if (!all_tids)
-                        return -ENOMEM;
-
-                all_tids[0] = target_tid;
-                thread_num = 1;
-        }
-
         list_for_each_entry(pos, &evsel_list, node) {
                 if (perf_evsel__alloc_stat_priv(pos) < 0 ||
                     perf_evsel__alloc_counts(pos, cpus->nr) < 0 ||
-                    perf_evsel__alloc_fd(pos, cpus->nr, thread_num) < 0)
+                    perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
                         goto out_free_fd;
         }
 
@@ -752,5 +743,7 @@ out_free_fd:
         list_for_each_entry(pos, &evsel_list, node)
                 perf_evsel__free_stat_priv(pos);
 out:
+        thread_map__delete(threads);
+        threads = NULL;
         return status;
 }
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 0e426665716d..1e67ab9c7ebc 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -68,8 +68,7 @@ static int			print_entries;
 
 static int                      target_pid                      =     -1;
 static int                      target_tid                      =     -1;
-static pid_t                    *all_tids                       =      NULL;
-static int                      thread_num                      =      0;
+static struct thread_map        *threads;
 static bool                     inherit                         =  false;
 static struct cpu_map           *cpus;
 static int                      realtime_prio                   =      0;
@@ -1200,7 +1199,7 @@ static void perf_session__mmap_read(struct perf_session *self)
         for (i = 0; i < cpus->nr; i++) {
                 list_for_each_entry(counter, &evsel_list, node) {
                         for (thread_index = 0;
-                                thread_index < thread_num;
+                                thread_index < threads->nr;
                                 thread_index++) {
                                 perf_session__mmap_read_counter(self,
                                         counter, i, thread_index);
@@ -1236,10 +1235,10 @@ static void start_counter(int i, struct perf_evsel *evsel)
         attr->inherit           = (cpu < 0) && inherit;
         attr->mmap              = 1;
 
-        for (thread_index = 0; thread_index < thread_num; thread_index++) {
+        for (thread_index = 0; thread_index < threads->nr; thread_index++) {
 try_again:
                 FD(evsel, i, thread_index) = sys_perf_event_open(attr,
-                                all_tids[thread_index], cpu, group_fd, 0);
+                                threads->map[thread_index], cpu, group_fd, 0);
 
                 if (FD(evsel, i, thread_index) < 0) {
                         int err = errno;
@@ -1410,25 +1409,17 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
         if (argc)
                 usage_with_options(top_usage, options);
 
-        if (target_pid != -1) {
+        if (target_pid != -1)
                 target_tid = target_pid;
-                thread_num = find_all_tid(target_pid, &all_tids);
-                if (thread_num <= 0) {
-                        fprintf(stderr, "Can't find all threads of pid %d\n",
-                                target_pid);
-                        usage_with_options(top_usage, options);
-                }
-        } else {
-                all_tids=malloc(sizeof(pid_t));
-                if (!all_tids)
-                        return -ENOMEM;
 
-                all_tids[0] = target_tid;
-                thread_num = 1;
+        threads = thread_map__new(target_pid, target_tid);
+        if (threads == NULL) {
+                pr_err("Problems finding threads of monitor\n");
+                usage_with_options(top_usage, options);
         }
 
-        event_array = malloc(
-                sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
+        event_array = malloc((sizeof(struct pollfd) *
+                              MAX_NR_CPUS * MAX_COUNTERS * threads->nr));
         if (!event_array)
                 return -ENOMEM;
 
@@ -1468,8 +1459,8 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
                 usage_with_options(top_usage, options);
 
         list_for_each_entry(pos, &evsel_list, node) {
-                if (perf_evsel__alloc_mmap_per_thread(pos, cpus->nr, thread_num) < 0 ||
-                    perf_evsel__alloc_fd(pos, cpus->nr, thread_num) < 0)
+                if (perf_evsel__alloc_mmap_per_thread(pos, cpus->nr, threads->nr) < 0 ||
+                    perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
                         goto out_free_fd;
                 /*
                  * Fill in the ones not specifically initialized via -c:
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 8c72d888e449..00f4eade2e3e 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -16,35 +16,50 @@ static int filter(const struct dirent *dir)
                 return 1;
 }
 
-int find_all_tid(int pid, pid_t ** all_tid)
+struct thread_map *thread_map__new_by_pid(pid_t pid)
 {
+        struct thread_map *threads;
         char name[256];
         int items;
         struct dirent **namelist = NULL;
-        int ret = 0;
         int i;
 
         sprintf(name, "/proc/%d/task", pid);
         items = scandir(name, &namelist, filter, NULL);
         if (items <= 0)
-                return -ENOENT;
-        *all_tid = malloc(sizeof(pid_t) * items);
-        if (!*all_tid) {
-                ret = -ENOMEM;
-                goto failure;
-        }
-
-        for (i = 0; i < items; i++)
-                (*all_tid)[i] = atoi(namelist[i]->d_name);
+                return NULL;
 
-        ret = items;
+        threads = malloc(sizeof(*threads) + sizeof(pid_t) * items);
+        if (threads != NULL) {
+                for (i = 0; i < items; i++)
+                        threads->map[i] = atoi(namelist[i]->d_name);
+                threads->nr = items;
+        }
 
-failure:
         for (i=0; i<items; i++)
                 free(namelist[i]);
         free(namelist);
 
-        return ret;
+        return threads;
+}
+
+struct thread_map *thread_map__new_by_tid(pid_t tid)
+{
+        struct thread_map *threads = malloc(sizeof(*threads) + sizeof(pid_t));
+
+        if (threads != NULL) {
+                threads->map[0] = tid;
+                threads->nr     = 1;
+        }
+
+        return threads;
+}
+
+struct thread_map *thread_map__new(pid_t pid, pid_t tid)
+{
+        if (pid != -1)
+                return thread_map__new_by_pid(pid);
+        return thread_map__new_by_tid(tid);
 }
 
 static struct thread *thread__new(pid_t pid)
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 688500ff826f..d7574101054a 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -18,11 +18,24 @@ struct thread {
         int                     comm_len;
 };
 
+struct thread_map {
+        int nr;
+        int map[];
+};
+
 struct perf_session;
 
 void thread__delete(struct thread *self);
 
-int find_all_tid(int pid, pid_t ** all_tid);
+struct thread_map *thread_map__new_by_pid(pid_t pid);
+struct thread_map *thread_map__new_by_tid(pid_t tid);
+struct thread_map *thread_map__new(pid_t pid, pid_t tid);
+
+static inline void thread_map__delete(struct thread_map *threads)
+{
+        free(threads);
+}
+
 int thread__set_comm(struct thread *self, const char *comm);
 int thread__comm_len(struct thread *self);
 struct thread *perf_session__findnew(struct perf_session *self, pid_t pid);