Commit 7cb2a53f authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
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perf record: Allow to specify max stack depth of fp callchain 



Currently it has no interface to specify the max stack depth for perf
record.  Extend the command line parameter to accept a number after
'fp' to specify the depth like '--call-graph fp,32'.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220615163222.1275500-7-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 3ae03f26

tools/perf/Documentation/perf-record.txt

+5 −0
Original line number Diff line number Diff line
@@ -275,6 +275,11 @@ OPTIONS 
	User can change the size by passing the size after comma like

	"--call-graph dwarf,4096".



	When "fp" recording is used, perf tries to save stack enties

	up to the number specified in sysctl.kernel.perf_event_max_stack

	by default.  User can change the number by passing it after comma

	like "--call-graph fp,32".



-q::

--quiet::

	Don't print any message, useful for scripting.

tools/perf/util/callchain.c

+12 −6
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include "callchain.h"

#include "branch.h"

#include "symbol.h"

#include "util.h"

#include "../perf.h"



#define CALLCHAIN_PARAM_DEFAULT			\
@@ -266,12 +267,17 @@ int parse_callchain_record(const char *arg, struct callchain_param *param) 
	do {

		/* Framepointer style */

		if (!strncmp(name, "fp", sizeof("fp"))) {

			if (!strtok_r(NULL, ",", &saveptr)) {

				param->record_mode = CALLCHAIN_FP;

			ret = 0;

			} else

				pr_err("callchain: No more arguments "

				       "needed for --call-graph fp\n");

			param->record_mode = CALLCHAIN_FP;



			tok = strtok_r(NULL, ",", &saveptr);

			if (tok) {

				unsigned long size;



				size = strtoul(tok, &name, 0);

				if (size < (unsigned) sysctl__max_stack())

					param->max_stack = size;

			}

			break;



		/* Dwarf style */