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 <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Anton Blanchard <[e-mail]>
LKML-Reference: <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

tools/perf/builtin-report.c

···
 
 static u64		sample_type;
 
-static size_t ipchain__fprintf_graph_line(FILE *fp, int depth, int depth_mask)
+
+static size_t
+callchain__fprintf_left_margin(FILE *fp, int left_margin)
+{
+	int i;
+	int ret;
+
+	ret = fprintf(fp, "            ");
+
+	for (i = 0; i < left_margin; i++)
+		ret += fprintf(fp, " ");
+
+	return ret;
+}
+
+static size_t ipchain__fprintf_graph_line(FILE *fp, int depth, int depth_mask,
+					  int left_margin)
 {
 	int i;
 	size_t ret = 0;
 
-	ret += fprintf(fp, "%s", "                ");
+	ret += callchain__fprintf_left_margin(fp, left_margin);
 
 	for (i = 0; i < depth; i++)
 		if (depth_mask & (1 << i))
···
 static size_t
 ipchain__fprintf_graph(FILE *fp, struct callchain_list *chain, int depth,
 		       int depth_mask, int count, u64 total_samples,
-		       int hits)
+		       int hits, int left_margin)
 {
 	int i;
 	size_t ret = 0;
 
-	ret += fprintf(fp, "%s", "                ");
+	ret += callchain__fprintf_left_margin(fp, left_margin);
 	for (i = 0; i < depth; i++) {
 		if (depth_mask & (1 << i))
 			ret += fprintf(fp, "|");
···
 
 static size_t
 __callchain__fprintf_graph(FILE *fp, struct callchain_node *self,
-			   u64 total_samples, int depth, int depth_mask)
+			   u64 total_samples, int depth, int depth_mask,
+			   int left_margin)
 {
 	struct rb_node *node, *next;
 	struct callchain_node *child;
···
 		 * But we keep the older depth mask for the line seperator
 		 * to keep the level link until we reach the last child
 		 */
-		ret += ipchain__fprintf_graph_line(fp, depth, depth_mask);
+		ret += ipchain__fprintf_graph_line(fp, depth, depth_mask,
+						   left_margin);
 		i = 0;
 		list_for_each_entry(chain, &child->val, list) {
 			if (chain->ip >= PERF_CONTEXT_MAX)
···
 			ret += ipchain__fprintf_graph(fp, chain, depth,
 						      new_depth_mask, i++,
 						      new_total,
-						      cumul);
+						      cumul,
+						      left_margin);
 		}
 		ret += __callchain__fprintf_graph(fp, child, new_total,
 						  depth + 1,
-						  new_depth_mask | (1 << depth));
+						  new_depth_mask | (1 << depth),
+						  left_margin);
 		node = next;
 	}
 
···
 
 		ret += ipchain__fprintf_graph(fp, &rem_hits, depth,
 					      new_depth_mask, 0, new_total,
-					      remaining);
+					      remaining, left_margin);
 	}
 
 	return ret;
 }
 
+
 static size_t
 callchain__fprintf_graph(FILE *fp, struct callchain_node *self,
-			 u64 total_samples)
+			 u64 total_samples, int left_margin)
 {
 	struct callchain_list *chain;
+	bool printed = false;
 	int i = 0;
 	int ret = 0;
 
···
 		if (chain->ip >= PERF_CONTEXT_MAX)
 			continue;
 
-		if (!i++ && sort_by_sym_first)
+		if (!i++ && sort__first_dimension == SORT_SYM)
 			continue;
 
+		if (!printed) {
+			ret += callchain__fprintf_left_margin(fp, left_margin);
+			ret += fprintf(fp, "|\n");
+			ret += callchain__fprintf_left_margin(fp, left_margin);
+			ret += fprintf(fp, "---");
+
+			left_margin += 3;
+			printed = true;
+		} else
+			ret += callchain__fprintf_left_margin(fp, left_margin);
+
 		if (chain->sym)
-			ret += fprintf(fp, "                %s\n", chain->sym->name);
+			ret += fprintf(fp, " %s\n", chain->sym->name);
 		else
-			ret += fprintf(fp, "                %p\n",
-					(void *)(long)chain->ip);
+			ret += fprintf(fp, " %p\n", (void *)(long)chain->ip);
 	}
 
-	ret += __callchain__fprintf_graph(fp, self, total_samples, 1, 1);
+	ret += __callchain__fprintf_graph(fp, self, total_samples, 1, 1, left_margin);
 
 	return ret;
 }
···
 
 static size_t
 hist_entry_callchain__fprintf(FILE *fp, struct hist_entry *self,
-			      u64 total_samples)
+			      u64 total_samples, int left_margin)
 {
 	struct rb_node *rb_node;
 	struct callchain_node *chain;
···
 			break;
 		case CHAIN_GRAPH_ABS: /* Falldown */
 		case CHAIN_GRAPH_REL:
-			ret += callchain__fprintf_graph(fp, chain, total_samples);
+			ret += callchain__fprintf_graph(fp, chain, total_samples,
+							left_margin);
 		case CHAIN_NONE:
 		default:
 			break;
···
 
 	ret += fprintf(fp, "\n");
 
-	if (callchain)
-		hist_entry_callchain__fprintf(fp, self, total_samples);
+	if (callchain) {
+		int left_margin = 0;
+
+		if (sort__first_dimension == SORT_COMM) {
+			se = list_first_entry(&hist_entry__sort_list, typeof(*se),
+						list);
+			left_margin = se->width ? *se->width : 0;
+			left_margin -= thread__comm_len(self->thread);
+		}
+
+		hist_entry_callchain__fprintf(fp, self, total_samples,
+					      left_margin);
+	}
 
 	return ret;
 }

tools/perf/util/sort.c

···
 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;
···
 			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;

tools/perf/util/sort.h

···
 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;
···
 	struct symbol		*parent;
 	struct callchain_node	callchain;
 	struct rb_root		sorted_chain;
+};
+
+enum sort_type {
+	SORT_PID,
+	SORT_COMM,
+	SORT_DSO,
+	SORT_SYM,
+	SORT_PARENT
 };
 
 /*

tools/perf/util/thread.c

···
 	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;

tools/perf/util/thread.h

···
 	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);