perf: Disable PERF_SAMPLE_BRANCH_* when not supported
PERF_SAMPLE_BRANCH_* is disabled for:
- SW events (sw counters, tracepoints)
- HW breakpoints
- ALL but Intel x86 architecture
- AMD64 processors
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1328826068-11713-10-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5820efd..242bb51 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5044,6 +5044,12 @@
if (event->attr.type != PERF_TYPE_SOFTWARE)
return -ENOENT;
+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event_id) {
case PERF_COUNT_SW_CPU_CLOCK:
case PERF_COUNT_SW_TASK_CLOCK:
@@ -5154,6 +5160,12 @@
if (event->attr.type != PERF_TYPE_TRACEPOINT)
return -ENOENT;
+ /*
+ * no branch sampling for tracepoint events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
err = perf_trace_init(event);
if (err)
return err;
@@ -5379,6 +5391,12 @@
if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
return -ENOENT;
+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);
return 0;
@@ -5453,6 +5471,12 @@
if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
return -ENOENT;
+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);
return 0;
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 3330022..bb38c4d 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -581,6 +581,12 @@
if (bp->attr.type != PERF_TYPE_BREAKPOINT)
return -ENOENT;
+ /*
+ * no branch sampling for breakpoint events
+ */
+ if (has_branch_stack(bp))
+ return -EOPNOTSUPP;
+
err = register_perf_hw_breakpoint(bp);
if (err)
return err;