perf symbols: Cache /proc/kallsyms files by build-id
So that when we don't have a vmlinux handy we can store the
kallsyms for later use by 'perf report'.
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: <1263501006-14185-3-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 71d23e1..ae61e9f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -383,13 +383,14 @@
return ret;
}
-int kallsyms__parse(void *arg, int (*process_symbol)(void *arg, const char *name,
+int kallsyms__parse(const char *filename, void *arg,
+ int (*process_symbol)(void *arg, const char *name,
char type, u64 start))
{
char *line = NULL;
size_t n;
int err = 0;
- FILE *file = fopen("/proc/kallsyms", "r");
+ FILE *file = fopen(filename, "r");
if (file == NULL)
goto out_failure;
@@ -466,10 +467,11 @@
* so that we can in the next step set the symbol ->end address and then
* call kernel_maps__split_kallsyms.
*/
-static int dso__load_all_kallsyms(struct dso *self, struct map *map)
+static int dso__load_all_kallsyms(struct dso *self, const char *filename,
+ struct map *map)
{
struct process_kallsyms_args args = { .map = map, .dso = self, };
- return kallsyms__parse(&args, map__process_kallsym_symbol);
+ return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
}
/*
@@ -556,10 +558,10 @@
}
-static int dso__load_kallsyms(struct dso *self, struct map *map,
+static int dso__load_kallsyms(struct dso *self, const char *filename, struct map *map,
struct perf_session *session, symbol_filter_t filter)
{
- if (dso__load_all_kallsyms(self, map) < 0)
+ if (dso__load_all_kallsyms(self, filename, map) < 0)
return -1;
symbols__fixup_end(&self->symbols[map->type]);
@@ -1580,7 +1582,8 @@
struct perf_session *session, symbol_filter_t filter)
{
int err;
- bool is_kallsyms;
+ const char *kallsyms_filename = NULL;
+ char *kallsyms_allocated_filename = NULL;
if (vmlinux_path != NULL) {
int i;
@@ -1606,19 +1609,37 @@
*/
if (self->has_build_id) {
u8 kallsyms_build_id[BUILD_ID_SIZE];
+ char sbuild_id[BUILD_ID_SIZE * 2 + 1];
if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
sizeof(kallsyms_build_id)) == 0) {
- is_kallsyms = dso__build_id_equal(self, kallsyms_build_id);
- if (is_kallsyms)
+ if (dso__build_id_equal(self, kallsyms_build_id)) {
+ kallsyms_filename = "/proc/kallsyms";
goto do_kallsyms;
+ }
}
+
+ build_id__sprintf(self->build_id, sizeof(self->build_id),
+ sbuild_id);
+
+ if (asprintf(&kallsyms_allocated_filename,
+ "%s/.debug/[kernel.kallsyms]/%s",
+ getenv("HOME"), sbuild_id) != -1) {
+ if (access(kallsyms_filename, F_OK)) {
+ kallsyms_filename = kallsyms_allocated_filename;
+ goto do_kallsyms;
+ }
+ free(kallsyms_allocated_filename);
+ kallsyms_allocated_filename = NULL;
+ }
+
goto do_vmlinux;
}
- is_kallsyms = self->long_name[0] == '[';
- if (is_kallsyms)
+ if (self->long_name[0] == '[') {
+ kallsyms_filename = "/proc/kallsyms";
goto do_kallsyms;
+ }
do_vmlinux:
err = dso__load_vmlinux(self, map, session, self->long_name, filter);
@@ -1629,9 +1650,10 @@
pr_info("The file %s cannot be used, "
"trying to use /proc/kallsyms...", self->long_name);
do_kallsyms:
- err = dso__load_kallsyms(self, map, session, filter);
- if (err > 0 && !is_kallsyms)
+ err = dso__load_kallsyms(self, kallsyms_filename, map, session, filter);
+ if (err > 0 && kallsyms_filename == NULL)
dso__set_long_name(self, strdup("[kernel.kallsyms]"));
+ free(kallsyms_allocated_filename);
}
if (err > 0) {
