perf tools: Use rb_tree for maps

Threads can have many and kernel modules will be represented as a
tree of maps as well.

Ah, and for a perf.data with 146607 samples:

Before:

[root@doppio ~]# perf stat -r 5 perf report > /dev/null

 Performance counter stats for 'perf report' (5 runs):

     699.823680  task-clock-msecs         #      0.991 CPUs    ( +-   0.454% )
             74  context-switches         #      0.000 M/sec   ( +-   1.709% )
              2  CPU-migrations           #      0.000 M/sec   ( +-  17.008% )
          23114  page-faults              #      0.033 M/sec   ( +-   0.000% )
     1381257019  cycles                   #   1973.721 M/sec   ( +-   0.290% )
     1456894438  instructions             #      1.055 IPC     ( +-   0.007% )
       18779818  cache-references         #     26.835 M/sec   ( +-   0.380% )
         641799  cache-misses             #      0.917 M/sec   ( +-   1.200% )

    0.705972729  seconds time elapsed   ( +-   0.501% )

[root@doppio ~]#

After

 Performance counter stats for 'perf report' (5 runs):

     691.261451  task-clock-msecs         #      0.993 CPUs    ( +-   0.307% )
             72  context-switches         #      0.000 M/sec   ( +-   0.829% )
              6  CPU-migrations           #      0.000 M/sec   ( +-  18.409% )
          23127  page-faults              #      0.033 M/sec   ( +-   0.000% )
     1366395876  cycles                   #   1976.670 M/sec   ( +-   0.153% )
     1443136016  instructions             #      1.056 IPC     ( +-   0.012% )
       17956402  cache-references         #     25.976 M/sec   ( +-   0.325% )
         661924  cache-misses             #      0.958 M/sec   ( +-   1.335% )

    0.696127275  seconds time elapsed   ( +-   0.377% )

I.e. we see some speedup too.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
LKML-Reference: <20090928174846.GA3361@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 83 insertions, 46 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 45efb5db0d1..9d0945cc66d 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -15,7 +15,7 @@ static struct thread *thread__new(pid_t pid)
                 self->comm = malloc(32);
                 if (self->comm)
                         snprintf(self->comm, 32, ":%d", self->pid);
-                INIT_LIST_HEAD(&self->maps);
+                self->maps = RB_ROOT;
         }
 
         return self;
@@ -31,11 +31,13 @@ int thread__set_comm(struct thread *self, const char *comm)
 
 static size_t thread__fprintf(struct thread *self, FILE *fp)
 {
-        struct map *pos;
+        struct rb_node *nd;
         size_t ret = fprintf(fp, "Thread %d %s\n", self->pid, self->comm);
 
-        list_for_each_entry(pos, &self->maps, node)
+        for (nd = rb_first(&self->maps); nd; nd = rb_next(nd)) {
+                struct map *pos = rb_entry(nd, struct map, rb_node);
                 ret += map__fprintf(pos, fp);
+        }
 
         return ret;
 }
@@ -93,42 +95,90 @@ register_idle_thread(struct rb_root *threads, struct thread **last_match)
         return thread;
 }
 
-void thread__insert_map(struct thread *self, struct map *map)
+static void thread__remove_overlappings(struct thread *self, struct map *map)
 {
-        struct map *pos, *tmp;
-
-        list_for_each_entry_safe(pos, tmp, &self->maps, node) {
-                if (map__overlap(pos, map)) {
-                        if (verbose >= 2) {
-                                printf("overlapping maps:\n");
-                                map__fprintf(map, stdout);
-                                map__fprintf(pos, stdout);
-                        }
-
-                        if (map->start <= pos->start && map->end > pos->start)
-                                pos->start = map->end;
-
-                        if (map->end >= pos->end && map->start < pos->end)
-                                pos->end = map->start;
-
-                        if (verbose >= 2) {
-                                printf("after collision:\n");
-                                map__fprintf(pos, stdout);
-                        }
-
-                        if (pos->start >= pos->end) {
-                                list_del_init(&pos->node);
-                                free(pos);
-                        }
+        struct rb_node *next = rb_first(&self->maps);
+
+        while (next) {
+                struct map *pos = rb_entry(next, struct map, rb_node);
+                next = rb_next(&pos->rb_node);
+
+                if (!map__overlap(pos, map))
+                        continue;
+
+                if (verbose >= 2) {
+                        printf("overlapping maps:\n");
+                        map__fprintf(map, stdout);
+                        map__fprintf(pos, stdout);
+                }
+
+                if (map->start <= pos->start && map->end > pos->start)
+                        pos->start = map->end;
+
+                if (map->end >= pos->end && map->start < pos->end)
+                        pos->end = map->start;
+
+                if (verbose >= 2) {
+                        printf("after collision:\n");
+                        map__fprintf(pos, stdout);
+                }
+
+                if (pos->start >= pos->end) {
+                        rb_erase(&pos->rb_node, &self->maps);
+                        free(pos);
                 }
         }
+}
+
+void maps__insert(struct rb_root *maps, struct map *map)
+{
+        struct rb_node **p = &maps->rb_node;
+        struct rb_node *parent = NULL;
+        const u64 ip = map->start;
+        struct map *m;
+
+        while (*p != NULL) {
+                parent = *p;
+                m = rb_entry(parent, struct map, rb_node);
+                if (ip < m->start)
+                        p = &(*p)->rb_left;
+                else
+                        p = &(*p)->rb_right;
+        }
+
+        rb_link_node(&map->rb_node, parent, p);
+        rb_insert_color(&map->rb_node, maps);
+}
+
+struct map *maps__find(struct rb_root *maps, u64 ip)
+{
+        struct rb_node **p = &maps->rb_node;
+        struct rb_node *parent = NULL;
+        struct map *m;
+
+        while (*p != NULL) {
+                parent = *p;
+                m = rb_entry(parent, struct map, rb_node);
+                if (ip < m->start)
+                        p = &(*p)->rb_left;
+                else if (ip > m->end)
+                        p = &(*p)->rb_right;
+                else
+                        return m;
+        }
+
+        return NULL;
+}
 
-        list_add_tail(&map->node, &self->maps);
+void thread__insert_map(struct thread *self, struct map *map)
+{
+        thread__remove_overlappings(self, map);
+        maps__insert(&self->maps, map);
 }
 
 int thread__fork(struct thread *self, struct thread *parent)
 {
-        struct map *map;
+        struct rb_node *nd;
 
         if (self->comm)
                 free(self->comm);
@@ -136,7 +186,8 @@ int thread__fork(struct thread *self, struct thread *parent)
         if (!self->comm)
                 return -ENOMEM;
 
-        list_for_each_entry(map, &parent->maps, node) {
+        for (nd = rb_first(&parent->maps); nd; nd = rb_next(nd)) {
+                struct map *map = rb_entry(nd, struct map, rb_node);
                 struct map *new = map__clone(map);
                 if (!new)
                         return -ENOMEM;
@@ -146,20 +197,6 @@ int thread__fork(struct thread *self, struct thread *parent)
         return 0;
 }
 
-struct map *thread__find_map(struct thread *self, u64 ip)
-{
-        struct map *pos;
-
-        if (self == NULL)
-                return NULL;
-
-        list_for_each_entry(pos, &self->maps, node)
-                if (ip >= pos->start && ip <= pos->end)
-                        return pos;
-
-        return NULL;
-}
-
 size_t threads__fprintf(FILE *fp, struct rb_root *threads)
 {
         size_t ret = 0;