DO NOT MERGE. Provided only to verify bug fix.
Change kernel and perf tool to activate tracking and context
switch for kernel branches.
Signed-off-by: David Carrillo-Cisneros <davi...@google.com>
---
arch/x86/events/intel/lbr.c | 3 ++-
tools/perf/util/evsel.c | 17 ++++++++++++++---
2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 6cd7cc0..ef3e275a39 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -388,7 +388,8 @@ void intel_pmu_lbr_sched_task(struct perf_event_context
*ctx, bool sched_in)
static inline bool branch_user_callstack(unsigned br_sel)
{
- return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK);
+ return (br_sel & (X86_BR_USER | X86_BR_KERNEL)) &&
+ (br_sel & X86_BR_CALL_STACK);
}
void intel_pmu_lbr_enable(struct perf_event *event)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 5d7037e..b39aafc 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -575,9 +575,20 @@ void perf_evsel__config_callchain(struct perf_evsel *evsel,
if (param->record_mode == CALLCHAIN_LBR) {
if (!opts->branch_stack) {
if (attr->exclude_user) {
- pr_warning("LBR callstack option is only
available "
- "to get user callchain information. "
- "Falling back to framepointers.\n");
+ /*
+ * Sample kernel AND user branches. Do not
exclude user
+ * branches because
task_ctx->lbr_callstack_users in
+ * arch/x86/events/intel/lbr.c only count users
for
+ * user branches.
+ */
+ pr_warning("BRANCH_STACK with kernel and
user\n");
+ perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
+ attr->branch_sample_type =
PERF_SAMPLE_BRANCH_KERNEL |
+ PERF_SAMPLE_BRANCH_USER
|
+
PERF_SAMPLE_BRANCH_CALL_STACK |
+
PERF_SAMPLE_BRANCH_NO_CYCLES |
+
PERF_SAMPLE_BRANCH_NO_FLAGS;
+
} else {
perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
attr->branch_sample_type =
PERF_SAMPLE_BRANCH_USER |
--
2.8.0.rc3.226.g39d4020
