perf top: Don't let events to eat up whole header line

Passing multiple events might force out information about pid/tid/cpu.
Attached patch leaves 30 characters for this info at the expense of the
events' names.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Han Pingtian <phan@redhat.com>
LKML-Reference: <1299528821-17521-3-git-send-email-jolsa@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index 4f869da4e9c7..75cfe4d45119 100644
--- a/tools/perf/util/top.c
+++ b/tools/perf/util/top.c
@@ -115,9 +115,23 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
         if (!top->display_weighted) {
                 ret += SNPRINTF(bf + ret, size - ret, "%s",
                                 event_name(top->sym_evsel));
-        } else list_for_each_entry(counter, &top->evlist->entries, node) {
-                ret += SNPRINTF(bf + ret, size - ret, "%s%s",
-                                counter->idx ? "/" : "", event_name(counter));
+        } else {
+                /*
+                 * Don't let events eat all the space. Leaving 30 bytes
+                 * for the rest should be enough.
+                 */
+                size_t last_pos = size - 30;
+
+                list_for_each_entry(counter, &top->evlist->entries, node) {
+                        ret += SNPRINTF(bf + ret, size - ret, "%s%s",
+                                        counter->idx ? "/" : "",
+                                        event_name(counter));
+                        if (ret > last_pos) {
+                                sprintf(bf + last_pos - 3, "..");
+                                ret = last_pos - 1;
+                                break;
+                        }
+                }
         }
 
         ret += SNPRINTF(bf + ret, size - ret, "], ");