[PATCH 1/1 perf-tools-next] perf top: Don't complain about lack of vmlinux when not resolving some kernel samples

From: Arnaldo Carvalho de Melo
Date: Fri Jan 03 2025 - 11:48:17 EST


Recently we got a case where a kernel sample wasn't being resolved due
to a bug that was not setting the end address on kernel functions
implemented in assembly (see Link: tag), and then those were not being
found by machine__resolve() -> map__find_symbol().

So we ended up with:

# perf top --stdio
PerfTop: 0 irqs/s kernel: 0% exact: 0% lost: 0/0 drop: 0/0 [cycles/P]
-----------------------------------------------------------------------

Warning:
A vmlinux file was not found.
Kernel samples will not be resolved.
^Z
[1]+ Stopped perf top --stdio
#

But then resolving all other kernel symbols.

So just fixup the logic to only print that warning when there are no
symbols in the kernel map.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lore.kernel.org/lkml/Z3buKhcCsZi3_aGb@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-top.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 724a7938632126bf..ca3e8eca6610e851 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -809,7 +809,7 @@ static void perf_event__process_sample(const struct perf_tool *tool,
* invalid --vmlinux ;-)
*/
if (!machine->kptr_restrict_warned && !top->vmlinux_warned &&
- __map__is_kernel(al.map) && map__has_symbols(al.map)) {
+ __map__is_kernel(al.map) && !map__has_symbols(al.map)) {
if (symbol_conf.vmlinux_name) {
char serr[256];

--
2.47.0