perf machine: Introduce number of threads member

To be used, for instance, for pre-allocating an rb_tree array for
sorting by other keys besides the current pid one.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ja0ifkwue7ttjhbwijn6g6eu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 2cb95bbf9ea67cb85ee3ce53240dab0bcb984f14..9d0913107dc774a22ac8502e34585d12a08bbe85 100644 (file)
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -32,6 +32,7 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
 
        machine->threads = RB_ROOT;
        pthread_rwlock_init(&machine->threads_lock, NULL);
+       machine->nr_threads = 0;
        INIT_LIST_HEAD(&machine->dead_threads);
        machine->last_match = NULL;
 
@@ -430,6 +431,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
                 */
                thread__get(th);
                machine->last_match = th;
+               ++machine->nr_threads;
        }
 
        return th;
@@ -681,11 +683,13 @@ size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
 
 size_t machine__fprintf(struct machine *machine, FILE *fp)
 {
-       size_t ret = 0;
+       size_t ret;
        struct rb_node *nd;
 
        pthread_rwlock_rdlock(&machine->threads_lock);
 
+       ret = fprintf(fp, "Threads: %u\n", machine->nr_threads);
+
        for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
                struct thread *pos = rb_entry(nd, struct thread, rb_node);
 
@@ -1419,6 +1423,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
                pthread_rwlock_wrlock(&machine->threads_lock);
        rb_erase_init(&th->rb_node, &machine->threads);
        RB_CLEAR_NODE(&th->rb_node);
+       --machine->nr_threads;
        /*
         * Move it first to the dead_threads list, then drop the reference,
         * if this is the last reference, then the thread__delete destructor

diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 4822de5e4544dd8fa56b19d3f044467f490d465b..83f46790c52f7e3008427577c52288ed5f15e86b 100644 (file)
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -31,6 +31,7 @@ struct machine {
        char              *root_dir;
        struct rb_root    threads;
        pthread_rwlock_t  threads_lock;
+       unsigned int      nr_threads;
        struct list_head  dead_threads;
        struct thread     *last_match;
        struct vdso_info  *vdso_info;