perf top: Improve the autosizing of column lenghts

When profiling C++ workloads the symbol name length can be
really big, so cap it before it garbles the result.

This builds upon the autosizing already present where we choose
to use the short, basename of DSOs instead of its long, full
pathname.

Reported-by: Pavel Krauz <krauz@cngroup.cz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1268676230-9261-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 15 insertions, 6 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 323c0aea0a9..c458c4a371d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -163,9 +163,17 @@ void dso__set_long_name(struct dso *self, char *name)
         self->long_name_len = strlen(name);
 }
 
+static void dso__set_short_name(struct dso *self, const char *name)
+{
+        if (name == NULL)
+                return;
+        self->short_name = name;
+        self->short_name_len = strlen(name);
+}
+
 static void dso__set_basename(struct dso *self)
 {
-        self->short_name = basename(self->long_name);
+        dso__set_short_name(self, basename(self->long_name));
 }
 
 struct dso *dso__new(const char *name)
@@ -176,7 +184,7 @@ struct dso *dso__new(const char *name)
                 int i;
                 strcpy(self->name, name);
                 dso__set_long_name(self, self->name);
-                self->short_name = self->name;
+                dso__set_short_name(self, self->name);
                 for (i = 0; i < MAP__NR_TYPES; ++i)
                         self->symbols[i] = self->symbol_names[i] = RB_ROOT;
                 self->slen_calculated = 0;
@@ -897,7 +905,6 @@ static int dso__load_sym(struct dso *self, struct map *map, const char *name,
         struct kmap *kmap = self->kernel ? map__kmap(map) : NULL;
         struct map *curr_map = map;
         struct dso *curr_dso = self;
-        size_t dso_name_len = strlen(self->short_name);
         Elf_Data *symstrs, *secstrs;
         uint32_t nr_syms;
         int err = -1;
@@ -987,7 +994,8 @@ static int dso__load_sym(struct dso *self, struct map *map, const char *name,
                         char dso_name[PATH_MAX];
 
                         if (strcmp(section_name,
-                                   curr_dso->short_name + dso_name_len) == 0)
+                                   (curr_dso->short_name +
+                                    self->short_name_len)) == 0)
                                 goto new_symbol;
 
                         if (strcmp(section_name, ".text") == 0) {
@@ -1782,7 +1790,7 @@ struct dso *dso__new_kernel(const char *name)
         struct dso *self = dso__new(name ?: "[kernel.kallsyms]");
 
         if (self != NULL) {
-                self->short_name = "[kernel]";
+                dso__set_short_name(self, "[kernel]");
                 self->kernel     = 1;
         }
 
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 280dadd32a0..f30a3742891 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -110,9 +110,10 @@ struct dso {
         u8               sorted_by_name;
         u8               loaded;
         u8               build_id[BUILD_ID_SIZE];
-        u16              long_name_len;
         const char       *short_name;
         char             *long_name;
+        u16              long_name_len;
+        u16              short_name_len;
         char             name[0];
 };