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Commit 37676af1 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent d87fcb4a

tools/perf/util/machine.c

+1 −1
Original line number Diff line number Diff line
@@ -1368,7 +1368,7 @@ int machine__resolve_callchain(struct machine *machine, 


	return unwind__get_entries(unwind_entry, &callchain_cursor, machine,

				   thread, evsel->attr.sample_regs_user,

				   sample);

				   sample, max_stack);



}

tools/perf/util/unwind.c

+5 −4
Original line number Diff line number Diff line
@@ -559,7 +559,7 @@ static unw_accessors_t accessors = { 
};



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 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, 
	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 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, 


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 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, 
	if (ret)

		return -ENOMEM;



	return get_entries(&ui, cb, arg);

	return get_entries(&ui, cb, arg, max_stack);

}

tools/perf/util/unwind.h

+3 −2
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, 
			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 @@ unwind__get_entries(unwind_entry_cb_t cb __maybe_unused, 
		    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;

}