perf symbols: Limit max callchain using max_stack on DWARF unwinding too
It was affecting only frame-pointer (fp) based callchain processing.
Usage example:
perf top --call-graph dwarf,1024 --max-stack 2
Works for any tool that does callchain resolving and provides a
--max-stack option.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/n/tip-eu45v8s3tq9ruay8tpfyon79@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 0393912..84cdb07 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1368,7 +1368,7 @@
return unwind__get_entries(unwind_entry, &callchain_cursor, machine,
thread, evsel->attr.sample_regs_user,
- sample);
+ sample, max_stack);
}
diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c
index 5390d0b..0efd539 100644
--- a/tools/perf/util/unwind.c
+++ b/tools/perf/util/unwind.c
@@ -559,7 +559,7 @@
};
static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
- void *arg)
+ void *arg, int max_stack)
{
unw_addr_space_t addr_space;
unw_cursor_t c;
@@ -575,7 +575,7 @@
if (ret)
display_error(ret);
- while (!ret && (unw_step(&c) > 0)) {
+ while (!ret && (unw_step(&c) > 0) && max_stack--) {
unw_word_t ip;
unw_get_reg(&c, UNW_REG_IP, &ip);
@@ -588,7 +588,8 @@
int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
struct machine *machine, struct thread *thread,
- u64 sample_uregs, struct perf_sample *data)
+ u64 sample_uregs, struct perf_sample *data,
+ int max_stack)
{
unw_word_t ip;
struct unwind_info ui = {
@@ -610,5 +611,5 @@
if (ret)
return -ENOMEM;
- return get_entries(&ui, cb, arg);
+ return get_entries(&ui, cb, arg, max_stack);
}
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index ec0c71a..d5966f49 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -18,7 +18,7 @@
struct machine *machine,
struct thread *thread,
u64 sample_uregs,
- struct perf_sample *data);
+ struct perf_sample *data, int max_stack);
int unwind__arch_reg_id(int regnum);
#else
static inline int
@@ -27,7 +27,8 @@
struct machine *machine __maybe_unused,
struct thread *thread __maybe_unused,
u64 sample_uregs __maybe_unused,
- struct perf_sample *data __maybe_unused)
+ struct perf_sample *data __maybe_unused,
+ int max_stack __maybe_unused)
{
return 0;
}