perf tools: Encode kernel module mappings in perf.data
We were always looking at the running machine /proc/modules,
even when processing a perf.data file, which only makes sense
when we're doing 'perf record' and 'perf report' on the same
machine, and in close sucession, or if we don't use modules at
all, right Peter? ;-)
Now, at 'perf record' time we read /proc/modules, find the long
path for modules, and put them as PERF_MMAP events, just like we
did to encode the reloc reference symbol for vmlinux. Talking
about that now it is encoded in .pgoff, so that we can use
.{start,len} to store the address boundaries for the kernel so
that when we reconstruct the kmaps tree we can do lookups right
away, without having to fixup the end of the kernel maps like we
did in the past (and now only in perf record).
One more step in the 'perf archive' direction when we'll finally
be able to collect data in one machine and analyse in another.
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: <1263396139-4798-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 88c570c..4af7199 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -494,6 +494,11 @@
if (!perf_session__has_traces(session, "kmem record"))
goto out_delete;
+ if (perf_session__create_kernel_maps(session) < 0) {
+ pr_err("Problems creating kernel maps\n");
+ return -1;
+ }
+
setup_pager();
err = perf_session__process_events(session, &event_ops);
if (err != 0)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8f88420..c130df26 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -465,6 +465,11 @@
return -1;
}
+ if (perf_session__create_kernel_maps(session) < 0) {
+ pr_err("Problems creating kernel maps\n");
+ return -1;
+ }
+
if (!file_new) {
err = perf_header__read(&session->header, output);
if (err < 0)
@@ -558,6 +563,12 @@
return err;
}
+ err = event__synthesize_modules(process_synthesized_event, session);
+ if (err < 0) {
+ pr_err("Couldn't record kernel reference relocation symbol.\n");
+ return err;
+ }
+
if (!system_wide && profile_cpu == -1)
event__synthesize_thread(pid, process_synthesized_event,
session);
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index ddc584b..6822b44 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1165,6 +1165,11 @@
if (session == NULL)
return -ENOMEM;
+ if (perf_session__create_kernel_maps(session) < 0) {
+ pr_err("Problems creating kernel maps\n");
+ return -1;
+ }
+
if (target_pid != -1)
event__synthesize_thread(target_pid, event__process, session);
else
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index bfb3d87..4f3e7ef 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -154,6 +154,36 @@
return 0;
}
+int event__synthesize_modules(event__handler_t process,
+ struct perf_session *session)
+{
+ struct rb_node *nd;
+
+ for (nd = rb_first(&session->kmaps.maps[MAP__FUNCTION]);
+ nd; nd = rb_next(nd)) {
+ event_t ev;
+ size_t size;
+ struct map *pos = rb_entry(nd, struct map, rb_node);
+
+ if (pos->dso->kernel)
+ continue;
+
+ size = ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
+ memset(&ev, 0, sizeof(ev));
+ ev.mmap.header.type = PERF_RECORD_MMAP;
+ ev.mmap.header.size = (sizeof(ev.mmap) -
+ (sizeof(ev.mmap.filename) - size));
+ ev.mmap.start = pos->start;
+ ev.mmap.len = pos->end - pos->start;
+
+ memcpy(ev.mmap.filename, pos->dso->long_name,
+ pos->dso->long_name_len + 1);
+ process(&ev, session);
+ }
+
+ return 0;
+}
+
int event__synthesize_thread(pid_t pid, event__handler_t process,
struct perf_session *session)
{
@@ -222,7 +252,9 @@
"[kernel.kallsyms.%s]", symbol_name) + 1;
size = ALIGN(size, sizeof(u64));
ev.mmap.header.size = (sizeof(ev.mmap) - (sizeof(ev.mmap.filename) - size));
- ev.mmap.start = args.start;
+ ev.mmap.pgoff = args.start;
+ ev.mmap.start = session->vmlinux_maps[MAP__FUNCTION]->start;
+ ev.mmap.len = session->vmlinux_maps[MAP__FUNCTION]->end - ev.mmap.start ;
return process(&ev, session);
}
@@ -280,7 +312,6 @@
{
struct thread *thread;
struct map *map;
- static const char kmmap_prefix[] = "[kernel.kallsyms.";
dump_printf(" %d/%d: [%p(%p) @ %p]: %s\n",
self->mmap.pid, self->mmap.tid,
@@ -289,13 +320,61 @@
(void *)(long)self->mmap.pgoff,
self->mmap.filename);
- if (self->mmap.pid == 0 &&
- memcmp(self->mmap.filename, kmmap_prefix,
- sizeof(kmmap_prefix) - 1) == 0) {
- const char *symbol_name = (self->mmap.filename +
- sizeof(kmmap_prefix) - 1);
- perf_session__set_kallsyms_ref_reloc_sym(session, symbol_name,
- self->mmap.start);
+ if (self->mmap.pid == 0) {
+ static const char kmmap_prefix[] = "[kernel.kallsyms.";
+
+ if (self->mmap.filename[0] == '/') {
+ char short_module_name[1024];
+ char *name = strrchr(self->mmap.filename, '/'), *dot;
+
+ if (name == NULL)
+ goto out_problem;
+
+ ++name; /* skip / */
+ dot = strrchr(name, '.');
+ if (dot == NULL)
+ goto out_problem;
+
+ snprintf(short_module_name, sizeof(short_module_name),
+ "[%.*s]", (int)(dot - name), name);
+ strxfrchar(short_module_name, '-', '_');
+
+ map = perf_session__new_module_map(session,
+ self->mmap.start,
+ short_module_name);
+ if (map == NULL)
+ goto out_problem;
+
+ name = strdup(self->mmap.filename);
+ if (name == NULL)
+ goto out_problem;
+
+ dso__set_long_name(map->dso, name);
+ map->end = map->start + self->mmap.len;
+ } else if (memcmp(self->mmap.filename, kmmap_prefix,
+ sizeof(kmmap_prefix) - 1) == 0) {
+ const char *symbol_name = (self->mmap.filename +
+ sizeof(kmmap_prefix) - 1);
+ /*
+ * Should be there already, from the build-id table in
+ * the header.
+ */
+ struct dso *kernel = __dsos__findnew(&dsos__kernel,
+ "[kernel.kallsyms]");
+ if (kernel == NULL)
+ goto out_problem;
+
+ if (__map_groups__create_kernel_maps(&session->kmaps,
+ session->vmlinux_maps,
+ kernel) < 0)
+ goto out_problem;
+
+ session->vmlinux_maps[MAP__FUNCTION]->start = self->mmap.start;
+ session->vmlinux_maps[MAP__FUNCTION]->end = self->mmap.start + self->mmap.len;
+
+ perf_session__set_kallsyms_ref_reloc_sym(session, symbol_name,
+ self->mmap.pgoff);
+ }
return 0;
}
@@ -304,10 +383,13 @@
session->cwd, session->cwdlen);
if (thread == NULL || map == NULL)
- dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
- else
- thread__insert_map(thread, map);
+ goto out_problem;
+ thread__insert_map(thread, map);
+ return 0;
+
+out_problem:
+ dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
return 0;
}
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 80356da..50a7132 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -112,6 +112,8 @@
int event__synthesize_kernel_mmap(event__handler_t process,
struct perf_session *session,
const char *symbol_name);
+int event__synthesize_modules(event__handler_t process,
+ struct perf_session *session);
int event__process_comm(event_t *self, struct perf_session *session);
int event__process_lost(event_t *self, struct perf_session *session);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 378ac54..fd1c5a3 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -69,9 +69,6 @@
self->unknown_events = 0;
map_groups__init(&self->kmaps);
- if (perf_session__create_kernel_maps(self) < 0)
- goto out_delete;
-
if (mode == O_RDONLY && perf_session__open(self, force) < 0)
goto out_delete;
@@ -268,8 +265,11 @@
head = &dsos__kernel;
dso = __dsos__findnew(head, filename);
- if (dso != NULL)
+ if (dso != NULL) {
dso__set_build_id(dso, &bev.build_id);
+ if (head == &dsos__kernel && filename[0] == '[')
+ dso->kernel = 1;
+ }
offset += bev.header.size;
}
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8e6627e..381999d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -161,7 +161,7 @@
self->start, self->end, self->name);
}
-static void dso__set_long_name(struct dso *self, char *name)
+void dso__set_long_name(struct dso *self, char *name)
{
if (name == NULL)
return;
@@ -176,7 +176,7 @@
struct dso *dso__new(const char *name)
{
- struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+ struct dso *self = zalloc(sizeof(*self) + strlen(name) + 1);
if (self != NULL) {
int i;
@@ -500,13 +500,17 @@
*module++ = '\0';
- if (strcmp(self->name, module)) {
+ if (strcmp(curr_map->dso->short_name, module)) {
curr_map = map_groups__find_by_name(&session->kmaps, map->type, module);
if (curr_map == NULL) {
pr_debug("/proc/{kallsyms,modules} "
- "inconsistency!\n");
+ "inconsistency while looking "
+ "for \"%s\" module!\n", module);
return -1;
}
+
+ if (curr_map->dso->loaded)
+ goto discard_symbol;
}
/*
* So that we look just like we get from .ko files,
@@ -1343,13 +1347,33 @@
for (nd = rb_first(&self->maps[type]); nd; nd = rb_next(nd)) {
struct map *map = rb_entry(nd, struct map, rb_node);
- if (map->dso && strcmp(map->dso->name, name) == 0)
+ if (map->dso && strcmp(map->dso->short_name, name) == 0)
return map;
}
return NULL;
}
+static int dso__kernel_module_get_build_id(struct dso *self)
+{
+ char filename[PATH_MAX];
+ /*
+ * kernel module short names are of the form "[module]" and
+ * we need just "module" here.
+ */
+ const char *name = self->short_name + 1;
+
+ snprintf(filename, sizeof(filename),
+ "/sys/module/%.*s/notes/.note.gnu.build-id",
+ (int)strlen(name - 1), name);
+
+ if (sysfs__read_build_id(filename, self->build_id,
+ sizeof(self->build_id)) == 0)
+ self->has_build_id = true;
+
+ return 0;
+}
+
static int perf_session__set_modules_path_dir(struct perf_session *self, char *dirname)
{
struct dirent *dent;
@@ -1395,6 +1419,7 @@
if (long_name == NULL)
goto failure;
dso__set_long_name(map->dso, long_name);
+ dso__kernel_module_get_build_id(map->dso);
}
}
@@ -1437,6 +1462,24 @@
return self;
}
+struct map *perf_session__new_module_map(struct perf_session *self, u64 start,
+ const char *filename)
+{
+ struct map *map;
+ struct dso *dso = __dsos__findnew(&dsos__kernel, filename);
+
+ if (dso == NULL)
+ return NULL;
+
+ map = map__new2(start, dso, MAP__FUNCTION);
+ if (map == NULL)
+ return NULL;
+
+ dso->origin = DSO__ORIG_KMODULE;
+ map_groups__insert(&self->kmaps, map);
+ return map;
+}
+
static int perf_session__create_module_maps(struct perf_session *self)
{
char *line = NULL;
@@ -1450,7 +1493,6 @@
while (!feof(file)) {
char name[PATH_MAX];
u64 start;
- struct dso *dso;
char *sep;
int line_len;
@@ -1476,26 +1518,10 @@
*sep = '\0';
snprintf(name, sizeof(name), "[%s]", line);
- dso = dso__new(name);
-
- if (dso == NULL)
+ map = perf_session__new_module_map(self, start, name);
+ if (map == NULL)
goto out_delete_line;
-
- map = map__new2(start, dso, MAP__FUNCTION);
- if (map == NULL) {
- dso__delete(dso);
- goto out_delete_line;
- }
-
- snprintf(name, sizeof(name),
- "/sys/module/%s/notes/.note.gnu.build-id", line);
- if (sysfs__read_build_id(name, dso->build_id,
- sizeof(dso->build_id)) == 0)
- dso->has_build_id = true;
-
- dso->origin = DSO__ORIG_KMODULE;
- map_groups__insert(&self->kmaps, map);
- dsos__add(&dsos__kernel, dso);
+ dso__kernel_module_get_build_id(map->dso);
}
free(line);
@@ -1573,10 +1599,28 @@
}
}
+ /*
+ * Say the kernel DSO was created when processing the build-id header table,
+ * we have a build-id, so check if it is the same as the running kernel,
+ * using it if it is.
+ */
+ if (self->has_build_id) {
+ u8 kallsyms_build_id[BUILD_ID_SIZE];
+
+ 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)
+ goto do_kallsyms;
+ goto do_vmlinux;
+ }
+
is_kallsyms = self->long_name[0] == '[';
if (is_kallsyms)
goto do_kallsyms;
+do_vmlinux:
err = dso__load_vmlinux(self, map, session, self->long_name, filter);
if (err <= 0) {
pr_info("The file %s cannot be used, "
@@ -1694,16 +1738,12 @@
return NULL;
}
-static int map_groups__create_kernel_maps(struct map_groups *self,
- struct map *vmlinux_maps[MAP__NR_TYPES],
- const char *vmlinux)
+int __map_groups__create_kernel_maps(struct map_groups *self,
+ struct map *vmlinux_maps[MAP__NR_TYPES],
+ struct dso *kernel)
{
- struct dso *kernel = dsos__create_kernel(vmlinux);
enum map_type type;
- if (kernel == NULL)
- return -1;
-
for (type = 0; type < MAP__NR_TYPES; ++type) {
vmlinux_maps[type] = map__new2(0, kernel, type);
if (vmlinux_maps[type] == NULL)
@@ -1717,6 +1757,18 @@
return 0;
}
+static int map_groups__create_kernel_maps(struct map_groups *self,
+ struct map *vmlinux_maps[MAP__NR_TYPES],
+ const char *vmlinux)
+{
+ struct dso *kernel = dsos__create_kernel(vmlinux);
+
+ if (kernel == NULL)
+ return -1;
+
+ return __map_groups__create_kernel_maps(self, vmlinux_maps, kernel);
+}
+
static void vmlinux_path__exit(void)
{
while (--vmlinux_path__nr_entries >= 0) {
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index ee0b459..594156e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -134,6 +134,7 @@
size_t dso__fprintf_buildid(struct dso *self, FILE *fp);
size_t dso__fprintf(struct dso *self, enum map_type type, FILE *fp);
char dso__symtab_origin(const struct dso *self);
+void dso__set_long_name(struct dso *self, char *name);
void dso__set_build_id(struct dso *self, void *build_id);
struct symbol *dso__find_symbol(struct dso *self, enum map_type type, u64 addr);
struct symbol *dso__find_symbol_by_name(struct dso *self, enum map_type type,
@@ -151,5 +152,7 @@
int perf_session__create_kernel_maps(struct perf_session *self);
+struct map *perf_session__new_module_map(struct perf_session *self, u64 start,
+ const char *filename);
extern struct dso *vdso;
#endif /* __PERF_SYMBOL */
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index c206f72..c06c135 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -67,4 +67,8 @@
struct map *map_groups__find_by_name(struct map_groups *self,
enum map_type type, const char *name);
+
+int __map_groups__create_kernel_maps(struct map_groups *self,
+ struct map *vmlinux_maps[MAP__NR_TYPES],
+ struct dso *kernel);
#endif /* __PERF_THREAD_H */