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Subject[PATCH 08/25] perf auxtrace: Add option to synthesize branch stacks on samples
Date
Add AUX area tracing option 'l' to synthesize branch stacks on samples
just like sample type PERF_SAMPLE_BRANCH_STACK. This is taken into use
by Intel PT in a subsequent patch.

Based-on-patch-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/Documentation/itrace.txt | 4 ++++
tools/perf/util/auxtrace.c | 20 ++++++++++++++++++++
tools/perf/util/auxtrace.h | 4 ++++
3 files changed, 28 insertions(+)

diff --git a/tools/perf/Documentation/itrace.txt b/tools/perf/Documentation/itrace.txt
index 2ff946677e3b..65453f4c7006 100644
--- a/tools/perf/Documentation/itrace.txt
+++ b/tools/perf/Documentation/itrace.txt
@@ -6,6 +6,7 @@
e synthesize error events
d create a debug log
g synthesize a call chain (use with i or x)
+ l synthesize last branch entries (use with i or x)

The default is all events i.e. the same as --itrace=ibxe

@@ -20,3 +21,6 @@

Also the call chain size (default 16, max. 1024) for instructions or
transactions events can be specified.
+
+ Also the number of last branch entries (default 64, max. 1024) for
+ instructions or transactions events can be specified.
diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index c4993b2e6c50..7f10430af39c 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -926,6 +926,8 @@ s64 perf_event__process_auxtrace(struct perf_tool *tool,
#define PERF_ITRACE_DEFAULT_PERIOD 100000
#define PERF_ITRACE_DEFAULT_CALLCHAIN_SZ 16
#define PERF_ITRACE_MAX_CALLCHAIN_SZ 1024
+#define PERF_ITRACE_DEFAULT_LAST_BRANCH_SZ 64
+#define PERF_ITRACE_MAX_LAST_BRANCH_SZ 1024

void itrace_synth_opts__set_default(struct itrace_synth_opts *synth_opts)
{
@@ -936,6 +938,7 @@ void itrace_synth_opts__set_default(struct itrace_synth_opts *synth_opts)
synth_opts->period_type = PERF_ITRACE_DEFAULT_PERIOD_TYPE;
synth_opts->period = PERF_ITRACE_DEFAULT_PERIOD;
synth_opts->callchain_sz = PERF_ITRACE_DEFAULT_CALLCHAIN_SZ;
+ synth_opts->last_branch_sz = PERF_ITRACE_DEFAULT_LAST_BRANCH_SZ;
}

/*
@@ -1043,6 +1046,23 @@ int itrace_parse_synth_opts(const struct option *opt, const char *str,
synth_opts->callchain_sz = val;
}
break;
+ case 'l':
+ synth_opts->last_branch = true;
+ synth_opts->last_branch_sz =
+ PERF_ITRACE_DEFAULT_LAST_BRANCH_SZ;
+ while (*p == ' ' || *p == ',')
+ p += 1;
+ if (isdigit(*p)) {
+ unsigned int val;
+
+ val = strtoul(p, &endptr, 10);
+ p = endptr;
+ if (!val ||
+ val > PERF_ITRACE_MAX_LAST_BRANCH_SZ)
+ goto out_err;
+ synth_opts->last_branch_sz = val;
+ }
+ break;
case ' ':
case ',':
break;
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index bf72b77a588a..b86f90db1352 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -63,7 +63,9 @@ enum itrace_period_type {
* @calls: limit branch samples to calls (can be combined with @returns)
* @returns: limit branch samples to returns (can be combined with @calls)
* @callchain: add callchain to 'instructions' events
+ * @last_branch: add branch context to 'instruction' events
* @callchain_sz: maximum callchain size
+ * @last_branch_sz: branch context size
* @period: 'instructions' events period
* @period_type: 'instructions' events period type
*/
@@ -79,7 +81,9 @@ struct itrace_synth_opts {
bool calls;
bool returns;
bool callchain;
+ bool last_branch;
unsigned int callchain_sz;
+ unsigned int last_branch_sz;
unsigned long long period;
enum itrace_period_type period_type;
};
--
1.9.1


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