[PATCH 2/9] perf, tools: Add --branch-history option to report v3

From: Andi Kleen
Date: Fri May 16 2014 - 13:06:29 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Add a --branch-history option to perf report that changes all
the settings necessary for using the branches in callstacks.

This is just a short cut to make this nicer to use, it does
not enable any functionality by itself.

v2: Change sort order. Rename option to --branch-history to
be less confusing.
v3: Updates
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
tools/perf/Documentation/perf-report.txt | 5 +++++
tools/perf/builtin-report.c | 33 +++++++++++++++++++++++++++-----
tools/perf/util/machine.c | 12 ++++++------
3 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 4f0f3d9..23bce9b 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -231,6 +231,11 @@ OPTIONS
branch stacks and it will automatically switch to the branch view mode,
unless --no-branch-stack is used.

+--branch-history::
+ Add the addresses of sampled taken branches to the callstack.
+ This allows to examine the path the program took to each sample.
+ The data collection must have used -b (or -j) and -g.
+
--objdump=<path>::
Path to objdump binary.

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 1a2d7fc..e6d8ed0 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -315,8 +315,9 @@ static int report__setup_sample_type(struct report *rep)
return -EINVAL;
}
if (symbol_conf.use_callchain) {
- ui__error("Selected -g but no callchain data. Did "
- "you call 'perf record' without -g?\n");
+ ui__error("Selected -g or --branch-history but no "
+ "callchain data. Did\n"
+ "you call 'perf record' without -g?\n");
return -1;
}
} else if (!rep->dont_use_callchains &&
@@ -631,6 +632,16 @@ parse_branch_mode(const struct option *opt __maybe_unused,
}

static int
+parse_branch_call_mode(const struct option *opt __maybe_unused,
+ const char *str __maybe_unused, int unset)
+{
+ int *branch_mode = opt->value;
+
+ *branch_mode = !unset;
+ return 0;
+}
+
+static int
parse_percent_limit(const struct option *opt, const char *str,
int unset __maybe_unused)
{
@@ -645,7 +656,7 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
struct perf_session *session;
struct stat st;
bool has_br_stack = false;
- int branch_mode = -1;
+ int branch_mode = -1, branch_call_mode = -1;
int ret = -1;
char callchain_default_opt[] = "fractal,0.5,callee";
const char * const report_usage[] = {
@@ -754,7 +765,11 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
OPT_BOOLEAN(0, "group", &symbol_conf.event_group,
"Show event group information together"),
OPT_CALLBACK_NOOPT('b', "branch-stack", &branch_mode, "",
- "use branch records for histogram filling", parse_branch_mode),
+ "use branch records for per branch histogram filling",
+ parse_branch_mode),
+ OPT_CALLBACK_NOOPT(0, "branch-history", &branch_call_mode, "",
+ "add last branch records to call history",
+ parse_branch_call_mode),
OPT_STRING(0, "objdump", &objdump_path, "path",
"objdump binary to use for disassembly and annotations"),
OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
@@ -804,8 +819,16 @@ repeat:
has_br_stack = perf_header__has_feat(&session->header,
HEADER_BRANCH_STACK);

- if (branch_mode == -1 && has_br_stack)
+ if (branch_mode == -1 && has_br_stack && branch_call_mode == -1)
sort__mode = SORT_MODE__BRANCH;
+ if (branch_call_mode != -1) {
+ callchain_param.branch_callstack = 1;
+ callchain_param.key = CCKEY_ADDRESS;
+ symbol_conf.use_callchain = true;
+ callchain_register_param(&callchain_param);
+ if (sort_order == default_sort_order)
+ sort_order = "srcline,symbol,dso";
+ }

/* sort__mode could be NORMAL if --no-branch-stack */
if (sort__mode == SORT_MODE__BRANCH) {
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 5238506..f828c87 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1379,15 +1379,15 @@ static int machine__resolve_callchain_sample(struct machine *machine,
* - No annotations (should annotate somehow)
*/

- if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
- pr_warning("corrupted branch chain. skipping...\n");
- return 0;
- }
-
- if (callchain_param.branch_callstack) {
+ if (branch && callchain_param.branch_callstack) {
int nr = min(max_stack, (int)branch->nr);
struct branch_entry be[nr];

+ if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
+ pr_warning("corrupted branch chain. skipping...\n");
+ return 0;
+ }
+
for (i = 0; i < nr; i++) {
if (callchain_param.order == ORDER_CALLEE) {
be[i] = branch->entries[i];
--
1.9.0

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