perf symbols: Add new option --ignore-vmlinux for perf top

Running "perf top" on a machine with possibly invalid or non-matching
vmlinux at the various places results in no symbol resolving despite
/proc/kallsyms being present and valid.

Add a new option --ignore-vmlinux to explicitly indicate that we do not
want to use these kernels and just use what we have (kallsyms).

Signed-off-by: Willy Tarreau <w@1wt.eu>
Cc: Ingo Molnar <mingo@redhat.com>
Link: http://lkml.kernel.org/r/20130914083259.GA3418@1wt.eu
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 5 insertions, 2 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index e8466956adbe..65c49b2f51c1 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1073,6 +1073,8 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
                     "list of cpus to monitor"),
         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
                    "file", "vmlinux pathname"),
+        OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux,
+                    "don't load vmlinux even if found"),
         OPT_BOOLEAN('K', "hide_kernel_symbols", &top.hide_kernel_symbols,
                     "hide kernel symbols"),
         OPT_CALLBACK('m', "mmap-pages", &opts->mmap_pages, "pages",
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index cd1dcc45049b..48c38791d61b 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1215,7 +1215,7 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map,
                 goto do_kallsyms;
         }
 
-        if (symbol_conf.vmlinux_name != NULL) {
+        if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
                 err = dso__load_vmlinux(dso, map,
                                         symbol_conf.vmlinux_name, filter);
                 if (err > 0) {
@@ -1227,7 +1227,7 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map,
                 return err;
         }
 
-        if (vmlinux_path != NULL) {
+        if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
                 err = dso__load_vmlinux_path(dso, map, filter);
                 if (err > 0)
                         return err;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 2a97bb1a8097..9b8b213a62c1 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -85,6 +85,7 @@ struct symbol_conf {
         unsigned short  priv_size;
         unsigned short  nr_events;
         bool            try_vmlinux_path,
+                        ignore_vmlinux,
                         show_kernel_path,
                         use_modules,
                         sort_by_name,