perf top: Teach it to autolocate vmlinux

By relying on logic in dso__load_kernel_sym(), we can
automatically load vmlinux.

The only thing which needs to be adjusted, is how --sym-annotate
option is handled - now we can't rely on vmlinux been loaded
until full successful pass of dso__load_vmlinux(), but that's
not the case if we'll do sym_filter_entry setup in
symbol_filter().

So move this step right after event__process_sample() where we
know the whole dso__load_kernel_sym() pass is done.

By the way, though conceptually similar `perf top` still can't
annotate userspace - see next patches with fixes.

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1265223128-11786-9-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 24 insertions, 17 deletions

diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index 4a7d558dc309..785b9fc32a46 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -74,7 +74,7 @@ OPTIONS
 
 -s <symbol>::
 --sym-annotate=<symbol>::
-        Annotate this symbol.  Requires -k option.
+        Annotate this symbol.
 
 -v::
 --verbose::
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 1fc018e048e1..83c09c8f28ed 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -94,6 +94,7 @@ struct source_line {
 
 static char                     *sym_filter                     =   NULL;
 struct sym_entry                *sym_filter_entry               =   NULL;
+struct sym_entry                *sym_filter_entry_sched         =   NULL;
 static int                      sym_pcnt_filter                 =      5;
 static int                      sym_counter                     =      0;
 static int                      display_weighted                =     -1;
@@ -695,11 +696,9 @@ static void print_mapped_keys(void)
 
         fprintf(stdout, "\t[f]     profile display filter (count).    \t(%d)\n", count_filter);
 
-        if (symbol_conf.vmlinux_name) {
-                fprintf(stdout, "\t[F]     annotate display filter (percent). \t(%d%%)\n", sym_pcnt_filter);
-                fprintf(stdout, "\t[s]     annotate symbol.                   \t(%s)\n", name?: "NULL");
-                fprintf(stdout, "\t[S]     stop annotation.\n");
-        }
+        fprintf(stdout, "\t[F]     annotate display filter (percent). \t(%d%%)\n", sym_pcnt_filter);
+        fprintf(stdout, "\t[s]     annotate symbol.                   \t(%s)\n", name?: "NULL");
+        fprintf(stdout, "\t[S]     stop annotation.\n");
 
         if (nr_counters > 1)
                 fprintf(stdout, "\t[w]     toggle display weighted/count[E]r. \t(%d)\n", display_weighted ? 1 : 0);
@@ -725,14 +724,13 @@ static int key_mapped(int c)
                 case 'Q':
                 case 'K':
                 case 'U':
+                case 'F':
+                case 's':
+                case 'S':
                         return 1;
                 case 'E':
                 case 'w':
                         return nr_counters > 1 ? 1 : 0;
-                case 'F':
-                case 's':
-                case 'S':
-                        return symbol_conf.vmlinux_name ? 1 : 0;
                 default:
                         break;
         }
@@ -910,8 +908,12 @@ static int symbol_filter(struct map *map, struct symbol *sym)
         syme = symbol__priv(sym);
         syme->map = map;
         syme->src = NULL;
-        if (!sym_filter_entry && sym_filter && !strcmp(name, sym_filter))
-                sym_filter_entry = syme;
+
+        if (!sym_filter_entry && sym_filter && !strcmp(name, sym_filter)) {
+                /* schedule initial sym_filter_entry setup */
+                sym_filter_entry_sched = syme;
+                sym_filter = NULL;
+        }
 
         for (i = 0; skip_symbols[i]; i++) {
                 if (!strcmp(skip_symbols[i], name)) {
@@ -976,6 +978,13 @@ static void event__process_sample(const event_t *self,
                 return;
         }
 
+        /* let's see, whether we need to install initial sym_filter_entry */
+        if (sym_filter_entry_sched) {
+                sym_filter_entry = sym_filter_entry_sched;
+                sym_filter_entry_sched = NULL;
+                parse_source(sym_filter_entry);
+        }
+
         syme = symbol__priv(al.sym);
         if (!syme->skip) {
                 syme->count[counter]++;
@@ -1270,7 +1279,7 @@ static const struct option options[] = {
         OPT_BOOLEAN('i', "inherit", &inherit,
                     "child tasks inherit counters"),
         OPT_STRING('s', "sym-annotate", &sym_filter, "symbol name",
-                    "symbol to annotate - requires -k option"),
+                    "symbol to annotate"),
         OPT_BOOLEAN('z', "zero", &zero,
                     "zero history across updates"),
         OPT_INTEGER('F', "freq", &freq,
@@ -1306,16 +1315,14 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 
         symbol_conf.priv_size = (sizeof(struct sym_entry) +
                                  (nr_counters + 1) * sizeof(unsigned long));
-        if (symbol_conf.vmlinux_name == NULL)
-                symbol_conf.try_vmlinux_path = true;
+
+        symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
         if (symbol__init() < 0)
                 return -1;
 
         if (delay_secs < 1)
                 delay_secs = 1;
 
-        parse_source(sym_filter_entry);
-
         /*
          * User specified count overrides default frequency.
          */