From 330aa675b4f92a422cb6d3acbbfd16a628017520 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Thu, 8 Mar 2012 23:47:46 +0100 Subject: [PATCH] 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: Stephane Eranian 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: Ingo Molnar --- tools/perf/builtin-record.c | 3 +++ tools/perf/util/header.c | 13 +++++++++++++ tools/perf/util/header.h | 2 +- 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index a7c53a9ef372..be4e1eee782e 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -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) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index c851495b9b48..0d9b6da86a39 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1023,6 +1023,12 @@ static int write_cpuid(int fd, struct perf_header *h __used, 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 { diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index e68f617d082f..21a6be09c129 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -27,7 +27,7 @@ enum { HEADER_EVENT_DESC, HEADER_CPU_TOPOLOGY, HEADER_NUMA_TOPOLOGY, - + HEADER_BRANCH_STACK, HEADER_LAST_FEATURE, HEADER_FEAT_BITS = 256, };