perf symbols: Do lazy symtab loading for the kernel & modules too

Just like we do with the other DSOs. This also simplifies the
kernel_maps setup process, now all that the tools need to do is
to call kernel_maps__init and the maps for the modules and
kernel will be created, then, later, when
kernel_maps__find_symbol() is used, it will also call
maps__find_symbol that already checks if the symtab was loaded,
loading it if needed.

Now if one does 'perf top --hide_kernel_symbols' we won't pay
the price of loading the (many) symbols in /proc/kallsyms or
vmlinux.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1258757489-5978-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 7 insertions, 28 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 48cc1084bc30..ea49c2e9dda3 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -830,6 +830,8 @@ static void handle_keypress(int c)
                 case 'q':
                 case 'Q':
                         printf("exiting.\n");
+                        if (dump_symtab)
+                                dsos__fprintf(stderr);
                         exit(0);
                 case 's':
                         prompt_symbol(&sym_filter_entry, "Enter details symbol");
@@ -946,30 +948,6 @@ static int symbol_filter(struct map *map, struct symbol *sym)
         return 0;
 }
 
-static int parse_symbols(void)
-{
-        struct dso *kernel = dsos__load_kernel();
-
-        if (kernel == NULL)
-                return -1;
-
-        if (dsos__load_modules() < 0)
-                pr_debug("Couldn't read the complete list of modules, "
-                         "continuing...\n");
-
-        if (dsos__load_modules_sym(symbol_filter) < 0)
-                pr_warning("Failed to read module symbols, continuing...\n");
-
-        if (dso__load_kernel_sym(kernel, symbol_filter, 1) <= 0)
-                pr_debug("Couldn't read the complete list of kernel symbols, "
-                         "continuing...\n");
-
-        if (dump_symtab)
-                dsos__fprintf(stderr);
-
-        return 0;
-}
-
 static void event__process_sample(const event_t *self, int counter)
 {
         u64 ip = self->ip.ip;
@@ -1012,7 +990,7 @@ static void event__process_sample(const event_t *self, int counter)
                 if (hide_kernel_symbols)
                         return;
 
-                sym = kernel_maps__find_symbol(ip, &map);
+                sym = kernel_maps__find_symbol(ip, &map, symbol_filter);
                 if (sym == NULL)
                         return;
                 break;
@@ -1339,7 +1317,7 @@ static const struct option options[] = {
 
 int cmd_top(int argc, const char **argv, const char *prefix __used)
 {
-        int counter;
+        int counter, err;
 
         page_size = sysconf(_SC_PAGE_SIZE);
 
@@ -1363,10 +1341,11 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
         if (delay_secs < 1)
                 delay_secs = 1;
 
-        parse_symbols();
+        err = kernel_maps__init(true);
+        if (err < 0)
+                return err;
         parse_source(sym_filter_entry);
 
-
         /*
          * User specified count overrides default frequency.
          */