perf tools: Disable user-space callchain/stack dumps for function trace events
User space callchains and user space stack dump were disabled
for function trace event. Mailing list discussions:
http://marc.info/?t=139302086500001&r=1&w=2
http://marc.info/?t=139301437300003&r=1&w=2
Catching up with perf and disabling user space callchains and
DWARF unwind (uses user stack dump) for function trace event.
Adding following warnings when callchains are used
for function trace event:
# perf record -g -e ftrace:function ...
Disabling user space callchains for function trace event.
...
# ./perf record --call-graph=dwarf -e ftrace:function ...
Cannot use DWARF unwind for function trace event, falling back to framepointers.
Disabling user space callchains for function trace event.
...
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1393775800-13524-4-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index adc94dd..26b67b1 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -500,6 +500,34 @@
return ret;
}
+static void
+perf_evsel__config_callgraph(struct perf_evsel *evsel,
+ struct record_opts *opts)
+{
+ bool function = perf_evsel__is_function_event(evsel);
+ struct perf_event_attr *attr = &evsel->attr;
+
+ perf_evsel__set_sample_bit(evsel, CALLCHAIN);
+
+ if (opts->call_graph == CALLCHAIN_DWARF) {
+ if (!function) {
+ perf_evsel__set_sample_bit(evsel, REGS_USER);
+ perf_evsel__set_sample_bit(evsel, STACK_USER);
+ attr->sample_regs_user = PERF_REGS_MASK;
+ attr->sample_stack_user = opts->stack_dump_size;
+ attr->exclude_callchain_user = 1;
+ } else {
+ pr_info("Cannot use DWARF unwind for function trace event,"
+ " falling back to framepointers.\n");
+ }
+ }
+
+ if (function) {
+ pr_info("Disabling user space callchains for function trace event.\n");
+ attr->exclude_callchain_user = 1;
+ }
+}
+
/*
* The enable_on_exec/disabled value strategy:
*
@@ -595,17 +623,8 @@
attr->mmap_data = track;
}
- if (opts->call_graph_enabled) {
- perf_evsel__set_sample_bit(evsel, CALLCHAIN);
-
- if (opts->call_graph == CALLCHAIN_DWARF) {
- perf_evsel__set_sample_bit(evsel, REGS_USER);
- perf_evsel__set_sample_bit(evsel, STACK_USER);
- attr->sample_regs_user = PERF_REGS_MASK;
- attr->sample_stack_user = opts->stack_dump_size;
- attr->exclude_callchain_user = 1;
- }
- }
+ if (opts->call_graph_enabled)
+ perf_evsel__config_callgraph(evsel, opts);
if (target__has_cpu(&opts->target))
perf_evsel__set_sample_bit(evsel, CPU);