Commit 330aa675 authored by Stephane Eranian's avatar Stephane Eranian Committed by Ingo Molnar
Browse files

perf record: Add HEADER_BRANCH_STACK tag 



This patch adds a new feature bit, namely,
HEADER_BRANCH_STACK.  When present, it indicates
that sample records may contain branch stack.

This could be useful to a viewer to switch to
branch mode without having to parse all the
samples or without a specific cmdline option.

This will be used in a subsequent patch to
enhance perf report with branch stacks.

Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: acme@redhat.com
Cc: asharma@fb.com
Cc: ravitillo@lbl.gov
Cc: vweaver1@eecs.utk.edu
Cc: khandual@linux.vnet.ibm.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/1331246868-19905-3-git-send-email-eranian@google.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a5aabdac

tools/perf/builtin-record.c

+3 −0
Original line number Diff line number Diff line
@@ -473,6 +473,9 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv) 
	if (!have_tracepoints(&evsel_list->entries))

		perf_header__clear_feat(&session->header, HEADER_TRACE_INFO);



	if (!rec->opts.branch_stack)

		perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK);



	if (!rec->file_new) {

		err = perf_session__read_header(session, output);

		if (err < 0)

tools/perf/util/header.c

+13 −0
Original line number Diff line number Diff line
@@ -1023,6 +1023,12 @@ write_it: 
	return do_write_string(fd, buffer);

}



static int write_branch_stack(int fd __used, struct perf_header *h __used,

		       struct perf_evlist *evlist __used)

{

	return 0;

}



static void print_hostname(struct perf_header *ph, int fd, FILE *fp)

{

	char *str = do_read_string(fd, ph);
@@ -1315,6 +1321,12 @@ static void print_cpuid(struct perf_header *ph, int fd, FILE *fp) 
	free(str);

}



static void print_branch_stack(struct perf_header *ph __used, int fd __used,

			       FILE *fp)

{

	fprintf(fp, "# contains samples with branch stack\n");

}



static int __event_process_build_id(struct build_id_event *bev,

				    char *filename,

				    struct perf_session *session)
@@ -1519,6 +1531,7 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = { 
	FEAT_OPA(HEADER_CMDLINE,	cmdline),

	FEAT_OPF(HEADER_CPU_TOPOLOGY,	cpu_topology),

	FEAT_OPF(HEADER_NUMA_TOPOLOGY,	numa_topology),

	FEAT_OPA(HEADER_BRANCH_STACK,	branch_stack),

};



struct header_print_data {

tools/perf/util/header.h

+1 −1
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ enum { 
	HEADER_EVENT_DESC,

	HEADER_CPU_TOPOLOGY,

	HEADER_NUMA_TOPOLOGY,



	HEADER_BRANCH_STACK,

	HEADER_LAST_FEATURE,

	HEADER_FEAT_BITS	= 256,

};

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