[PATCH 2/5] perf report: Show message for percent limit on stdio

Namhyung Kim
2016-02-26T12:14:45Z

When the hierarchy mode is used, some entries might be omiited due to a
percent limit or filter. In this case the output hierarchy is different
than other entries. Add an informative message to users about this.

For example, when 4% of percent limit is applied:

Before:
# Overhead Command / Shared Object / Symbol
# .............. ..........................................
#
49.09% swapper
48.67% [kernel.vmlinux]
34.42% [k] intel_idle
11.51% firefox
8.87% libpthread-2.22.so
6.60% [.] __GI___libc_recvmsg
10.49% gnome-shell
4.74% libc-2.22.so
10.08% Xorg
6.11% libc-2.22.so
5.27% [.] __memcpy_sse2_unaligned
6.15% perf

Note that, gnome-shell/libc has no symbols and perf has no dso/symbols.
With that patch the output will look like below:

After:

# Overhead Command / Shared Object / Symbol
# .............. ..........................................
#
49.09% swapper
48.67% [kernel.vmlinux]
34.42% [k] intel_idle
11.51% firefox
8.87% libpthread-2.22.so
6.60% [.] __GI___libc_recvmsg
10.49% gnome-shell
4.74% libc-2.22.so
no entry >= 4.00%
10.08% Xorg
6.11% libc-2.22.so
5.27% [.] __memcpy_sse2_unaligned
6.15% perf
no entry >= 4.00%

Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/ui/stdio/hist.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
index 435eaaaf2f1d..b3bdfcb245f9 100644
--- a/tools/perf/ui/stdio/hist.c
+++ b/tools/perf/ui/stdio/hist.c
@@ -628,6 +628,7 @@ size_t hists__fprintf(struct hists *hists, bool show_header, int max_rows,
bool first = true;
size_t linesz;
char *line = NULL;
+ unsigned indent;

init_rem_hits();

@@ -704,6 +705,8 @@ print_entries:
goto out;
}

+ indent = hists__overhead_width(hists) + 4;
+
for (nd = rb_first(&hists->entries); nd; nd = __rb_hierarchy_next(nd, HMD_FORCE_CHILD)) {
struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
float percent;
@@ -720,6 +723,20 @@ print_entries:
if (max_rows && ++nr_rows >= max_rows)
break;

+ /*
+ * If all children are filtered out or percent-limited,
+ * display "no entry >= x.xx%" message.
+ */
+ if (!h->leaf && !hist_entry__has_hierarchy_children(h, min_pcnt)) {
+ int nr_sort = hists->hpp_list->nr_sort_keys;
+
+ print_hierarchy_indent(sep, nr_sort + h->depth + 1, spaces, fp);
+ fprintf(fp, "%*sno entry >= %.2f%%\n", indent, "", min_pcnt);
+
+ if (max_rows && ++nr_rows >= max_rows)
+ break;
+ }
+
if (h->ms.map == NULL && verbose > 1) {
__map_groups__fprintf_maps(h->thread->mg,
MAP__FUNCTION, fp);
--
2.7.1