Namhyung,
Can you take a look and perhaps give me your Acked-by?
- Arnaldo
From: Arnaldo Carvalho de Melo <a...@redhat.com>
No need to traverse it all again using the filename extension to
disambiguate kernel from kernel modules, just cache it when
reading the buildid table.
This also fixes a refcount bug in the error path, i.e. in the error path
for the __machine__create_kernel_maps() call we do a dso__put(), which
is ok and expected if that dso came from machine__findnew_dso(), but
wasn't when we found it by traversing the machine dso list without
grabbing a dso refcount (dso__get()) before dropping the list lock.
Fixes: b837a8bdc489 ("perf tools: Fix build-id matching on vmlinux")
Link: http://lkml.kernel.org/n/tip-48fh3cf6pvs4zs2fj4nhc...@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/util/header.c | 7 +++++++
tools/perf/util/machine.c | 34 +++-------------------------------
tools/perf/util/machine.h | 1 +
3 files changed, 11 insertions(+), 31 deletions(-)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 43838003c1a1..6bc92ae1e99a 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1260,6 +1260,13 @@ static int __event_process_build_id(struct
build_id_event *bev,
if (!is_kernel_module(filename, cpumode))
dso->kernel = dso_type;
+ /*
+ * We don't need to grab a reference as long as
+ * the kernel dso is in the machine dso list.
+ */
+ if (cpumode == PERF_RECORD_MISC_KERNEL ||
+ cpumode == PERF_RECORD_MISC_GUEST_KERNEL)
+ machine->kernel_dso = dso;
build_id__sprintf(dso->build_id, sizeof(dso->build_id),
sbuild_id);
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index d07a38678e14..f6e689b2c83c 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -62,6 +62,7 @@ int machine__init(struct machine *machine, const char
*root_dir, pid_t pid)
}
machine->current_tid = NULL;
+ machine->kernel_dso = NULL;
return 0;
}
@@ -1180,39 +1181,10 @@ static int machine__process_kernel_mmap_event(struct
machine *machine,
* Should be there already, from the build-id table in
* the header.
*/
- struct dso *kernel = NULL;
- struct dso *dso;
+ struct dso *kernel;
pthread_rwlock_rdlock(&machine->dsos.lock);
-
- list_for_each_entry(dso, &machine->dsos.head, node) {
-
- /*
- * The cpumode passed to is_kernel_module is not the
- * cpumode of *this* event. If we insist on passing
- * correct cpumode to is_kernel_module, we should
- * record the cpumode when we adding this dso to the
- * linked list.
- *
- * However we don't really need passing correct
- * cpumode. We know the correct cpumode must be kernel
- * mode (if not, we should not link it onto kernel_dsos
- * list).
- *
- * Therefore, we pass PERF_RECORD_MISC_CPUMODE_UNKNOWN.
- * is_kernel_module() treats it as a kernel cpumode.
- */
-
- if (!dso->kernel ||
- is_kernel_module(dso->long_name,
- PERF_RECORD_MISC_CPUMODE_UNKNOWN))
- continue;
-
-
- kernel = dso;
- break;
- }
-
+ kernel = dso__get(machine->kernel_dso);
pthread_rwlock_unlock(&machine->dsos.lock);
if (kernel == NULL)
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 9dfc4281f940..d7b044a1046f 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -38,6 +38,7 @@ struct machine {
struct dsos dsos;
struct map_groups kmaps;
struct map *vmlinux_maps[MAP__NR_TYPES];
+ struct dso *kernel_dso;
u64 kernel_start;
symbol_filter_t symbol_filter;
pid_t *current_tid;
--
2.1.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
