perf symbols: Retain bfd reference to lookup source line numbers

Closng and re-opening for every lookup when using libbfd to lookup
source file name and line number is very very slow. Instead keep the
reference on struct dso.

Signed-off-by: Adrian Hunter <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/dso.c

···
 	if (dso->lname_alloc)
 		free(dso->long_name);
 	dso_cache__free(&dso->cache);
+	dso__free_a2l(dso);
 	free(dso);
 }
 

tools/perf/util/dso.h

···
 	struct rb_root	 symbols[MAP__NR_TYPES];
 	struct rb_root	 symbol_names[MAP__NR_TYPES];
 	struct rb_root	 cache;
+	void		 *a2l;
 	enum dso_kernel_type	kernel;
 	enum dso_swap_type	needs_swap;
 	enum dso_binary_type	symtab_type;
···
 	return dso->data_type == DSO_BINARY_TYPE__KCORE ||
 	       dso->data_type == DSO_BINARY_TYPE__GUEST_KCORE;
 }
+
+void dso__free_a2l(struct dso *dso);
 
 #endif /* __PERF_DSO */

tools/perf/util/srcline.c

···
 }
 
 static int addr2line(const char *dso_name, unsigned long addr,
-		     char **file, unsigned int *line)
+		     char **file, unsigned int *line, struct dso *dso)
 {
 	int ret = 0;
-	struct a2l_data *a2l;
+	struct a2l_data *a2l = dso->a2l;
 
-	a2l = addr2line_init(dso_name);
+	if (!a2l) {
+		dso->a2l = addr2line_init(dso_name);
+		a2l = dso->a2l;
+	}
+
 	if (a2l == NULL) {
 		pr_warning("addr2line_init failed for %s\n", dso_name);
 		return 0;
 	}
 
 	a2l->addr = addr;
+	a2l->found = false;
+
 	bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);
 
 	if (a2l->found && a2l->filename) {
···
 			ret = 1;
 	}
 
-	addr2line_cleanup(a2l);
 	return ret;
+}
+
+void dso__free_a2l(struct dso *dso)
+{
+	struct a2l_data *a2l = dso->a2l;
+
+	if (!a2l)
+		return;
+
+	addr2line_cleanup(a2l);
+
+	dso->a2l = NULL;
 }
 
 #else /* HAVE_LIBBFD_SUPPORT */
 
 static int addr2line(const char *dso_name, unsigned long addr,
-		     char **file, unsigned int *line_nr)
+		     char **file, unsigned int *line_nr,
+		     struct dso *dso __maybe_unused)
 {
 	FILE *fp;
 	char cmd[PATH_MAX];
···
 	pclose(fp);
 	return ret;
 }
+
+void dso__free_a2l(struct dso *dso __maybe_unused)
+{
+}
+
 #endif /* HAVE_LIBBFD_SUPPORT */
 
 char *get_srcline(struct dso *dso, unsigned long addr)
···
 	if (!strncmp(dso_name, "/tmp/perf-", 10))
 		goto out;
 
-	if (!addr2line(dso_name, addr, &file, &line))
+	if (!addr2line(dso_name, addr, &file, &line, dso))
 		goto out;
 
 	if (asprintf(&srcline, "%s:%u", file, line) < 0)
···
 
 out:
 	dso->has_srcline = 0;
+	dso__free_a2l(dso);
 	return SRCLINE_UNKNOWN;
 }