perf tools: Bind callchains to the first sort dimension column

Currently, the callchains are displayed using a constant left
margin. So depending on the current sort dimension
configuration, callchains may appear to be well attached to the
first sort dimension column field which is mostly the case,
except when the first dimension of sorting is done by comm,
because these are right aligned.

This patch binds the callchain to the first letter in the first
column, whatever type of column it is (dso, comm, symbol).
Before:

     0.80%             perf  [k] __lock_acquire
             __lock_acquire
             lock_acquire
             |
             |--58.33%-- _spin_lock
             |          |
             |          |--28.57%-- inotify_should_send_event
             |          |          fsnotify
             |          |          __fsnotify_parent

After:

     0.80%             perf  [k] __lock_acquire
                       __lock_acquire
                       lock_acquire
                       |
                       |--58.33%-- _spin_lock
                       |          |
                       |          |--28.57%-- inotify_should_send_event
                       |          |          fsnotify
                       |          |          __fsnotify_parent

Also, for clarity, we don't put anymore the callchain as is but:

- If we have a top level ancestor in the callchain, start it
  with a first ascii hook.

  Before:

     0.80%             perf  [kernel]                        [k] __lock_acquire
                       __lock_acquire
                         lock_acquire
                       |
                       |--58.33%-- _spin_lock
                       |          |
                       |          |--28.57%-- inotify_should_send_event
                       |          |          fsnotify
                      [..]       [..]

   After:

     0.80%             perf  [kernel]                         [k] __lock_acquire
                       |
                       --- __lock_acquire
                           lock_acquire
                          |
                          |--58.33%-- _spin_lock
                          |          |
                          |          |--28.57%-- inotify_should_send_event
                          |          |          fsnotify
                         [..]       [..]

- Otherwise, if we have several top level ancestors, then
  display these like we did before:

       1.69%           Xorg
                       |
                       |--21.21%-- vread_hpet
                       |          0x7fffd85b46fc
                       |          0x7fffd85b494d
                       |          0x7f4fafb4e54d
                       |
                       |--15.15%-- exaOffscreenAlloc
                       |
                       |--9.09%-- I830WaitLpRing

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
LKML-Reference: <1256246604-17156-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 36 insertions, 5 deletions

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 60ced707bd6..b490354d1b2 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -7,7 +7,8 @@ char		default_sort_order[] = "comm,dso,symbol";
 char		*sort_order = default_sort_order;
 int		sort__need_collapse = 0;
 int		sort__has_parent = 0;
-int		sort_by_sym_first;
+
+enum sort_type	sort__first_dimension;
 
 unsigned int dsos__col_width;
 unsigned int comms__col_width;
@@ -266,9 +267,18 @@ int sort_dimension__add(const char *tok)
 			sort__has_parent = 1;
 		}
 
-		if (list_empty(&hist_entry__sort_list) &&
-		    !strcmp(sd->name, "symbol"))
-			sort_by_sym_first = true;
+		if (list_empty(&hist_entry__sort_list)) {
+			if (!strcmp(sd->name, "pid"))
+				sort__first_dimension = SORT_PID;
+			else if (!strcmp(sd->name, "comm"))
+				sort__first_dimension = SORT_COMM;
+			else if (!strcmp(sd->name, "dso"))
+				sort__first_dimension = SORT_DSO;
+			else if (!strcmp(sd->name, "symbol"))
+				sort__first_dimension = SORT_SYM;
+			else if (!strcmp(sd->name, "parent"))
+				sort__first_dimension = SORT_PARENT;
+		}
 
 		list_add_tail(&sd->entry->list, &hist_entry__sort_list);
 		sd->taken = 1;
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index 24c2b709f0d..333e664ff45 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -39,7 +39,7 @@ extern struct sort_entry sort_parent;
 extern unsigned int dsos__col_width;
 extern unsigned int comms__col_width;
 extern unsigned int threads__col_width;
-extern int sort_by_sym_first;
+extern enum sort_type sort__first_dimension;
 
 struct hist_entry {
 	struct rb_node		rb_node;
@@ -54,6 +54,14 @@ struct hist_entry {
 	struct rb_root		sorted_chain;
 };
 
+enum sort_type {
+	SORT_PID,
+	SORT_COMM,
+	SORT_DSO,
+	SORT_SYM,
+	SORT_PARENT
+};
+
 /*
  * configurable sorting bits
  */
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index f53fad7c0a8..8cb47f1d8a7 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -33,6 +33,17 @@ int thread__set_comm(struct thread *self, const char *comm)
 	return self->comm ? 0 : -ENOMEM;
 }
 
+int thread__comm_len(struct thread *self)
+{
+	if (!self->comm_len) {
+		if (!self->comm)
+			return 0;
+		self->comm_len = strlen(self->comm);
+	}
+
+	return self->comm_len;
+}
+
 static size_t thread__fprintf(struct thread *self, FILE *fp)
 {
 	struct rb_node *nd;
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 1abef3b7455..53addd77ce8 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -12,9 +12,11 @@ struct thread {
 	pid_t			pid;
 	char			shortname[3];
 	char			*comm;
+	int			comm_len;
 };
 
 int thread__set_comm(struct thread *self, const char *comm);
+int thread__comm_len(struct thread *self);
 struct thread *threads__findnew(pid_t pid);
 struct thread *register_idle_thread(void);
 void thread__insert_map(struct thread *self, struct map *map);