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>

3 files changed, 24 insertions, 10 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 0b719e3dde05..8364c8aba194 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -455,7 +455,7 @@ static void print_sym_table(void)
         struct sym_entry *syme, *n;
         struct rb_root tmp = RB_ROOT;
         struct rb_node *nd;
-        int sym_width = 0, dso_width = 0, max_dso_width;
+        int sym_width = 0, dso_width = 0, dso_short_width;
         const int win_width = winsize.ws_col - 1;
 
         samples = userspace_samples = 0;
@@ -545,15 +545,20 @@ static void print_sym_table(void)
                 if (syme->map->dso->long_name_len > dso_width)
                         dso_width = syme->map->dso->long_name_len;
 
+                if (syme->map->dso->short_name_len > dso_short_width)
+                        dso_short_width = syme->map->dso->short_name_len;
+
                 if (syme->name_len > sym_width)
                         sym_width = syme->name_len;
         }
 
         printed = 0;
 
-        max_dso_width = winsize.ws_col - sym_width - 29;
-        if (dso_width > max_dso_width)
-                dso_width = max_dso_width;
+        if (sym_width + dso_width > winsize.ws_col - 29) {
+                dso_width = dso_short_width;
+                if (sym_width + dso_width > winsize.ws_col - 29)
+                        sym_width = winsize.ws_col - dso_width - 29;
+        }
         putchar('\n');
         if (nr_counters == 1)
                 printf("             samples  pcnt");
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 323c0aea0a91..c458c4a371d1 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 280dadd32a08..f30a37428919 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];
 };