perf data: Add callchain to CTF conversion

The field perf_callchain, if available, is added to the sampling events
during the CTF conversion. It is an array of u64 values.  The
perf_callchain_size field contains the size of the array.

It will allow the analysis of sampling data in trace visualization tools
like Trace Compass. Possible analyses with those data: dynamic
flamegraphs, correlation with other tracing data like a userspace trace.

Here follows a babeltrace CTF output of a trace with callchain:

  $ babeltrace ./myctftrace
  [17:38:45.672760285] (+?.?????????) cycles:ppp: { cpu_id = 0 }, { perf_ip = 0xFFFFFFFF81063EE4, perf_tid = 25841, perf_pid = 25774, perf_period = 1, perf_callchain_size = 7, perf_callchain = [ [0] = 0xFFFFFFFFFFFFFF80, [1] = 0xFFFFFFFF81063EE4, [2] = 0xFFFFFFFF8100C770, [3] = 0xFFFFFFFF81006EC6, [4] = 0xFFFFFFFF8118245E, [5] = 0xFFFFFFFF810A9224, [6] = 0xFFFFFFFF8164A4C6 ] }
  [17:38:45.672777672] (+0.000017387) cycles:ppp: { cpu_id = 0 }, { perf_ip = 0xFFFFFFFF81063EE4, perf_tid = 25841, perf_pid = 25774, perf_period = 1, perf_callchain_size = 8, perf_callchain = [ [0] = 0xFFFFFFFFFFFFFF80, [1] = 0xFFFFFFFF81063EE4, [2] = 0xFFFFFFFF8100C770, [3] = 0xFFFFFFFF81006EC6, [4] = 0xFFFFFFFF8118245E, [5] = 0xFFFFFFFF810A9224, [6] = 0xFFFFFFFF8164A4C6, [7] = 0xFFFFFFFF8164ABAD ] }
  [17:38:45.672786700] (+0.000009028) cycles:ppp: { cpu_id = 0 }, { perf_ip = 0xFFFFFFFF81063EE4, perf_tid = 25841, perf_pid = 25774, perf_period = 70, perf_callchain_size = 3, perf_callchain = [ [0] = 0xFFFFFFFFFFFFFF80, [1] = 0xFFFFFFFF81063EE4, [2] = 0xFFFFFFFF8100C770 ] }

Signed-off-by: Geneviève Bastien <gbastien@versatic.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Julien Desfossez <jdesfossez@efficios.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170727181205.24843-1-gbastien@versatic.net
[ Removed PERF_SAMPLE_CALLCHAIN from the TODO list, jolsa ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
index 3149b70..eeb2590 100644 (file)
--- a/tools/perf/util/data-convert-bt.c
+++ b/tools/perf/util/data-convert-bt.c
@@ -506,6 +506,81 @@ put_len_type:
        return ret;
 }
 
+static int
+add_callchain_output_values(struct bt_ctf_event_class *event_class,
+                     struct bt_ctf_event *event,
+                     struct ip_callchain *callchain)
+{
+       struct bt_ctf_field_type *len_type, *seq_type;
+       struct bt_ctf_field *len_field, *seq_field;
+       unsigned int nr_elements = callchain->nr;
+       unsigned int i;
+       int ret;
+
+       len_type = bt_ctf_event_class_get_field_by_name(
+                       event_class, "perf_callchain_size");
+       len_field = bt_ctf_field_create(len_type);
+       if (!len_field) {
+               pr_err("failed to create 'perf_callchain_size' for callchain output event\n");
+               ret = -1;
+               goto put_len_type;
+       }
+
+       ret = bt_ctf_field_unsigned_integer_set_value(len_field, nr_elements);
+       if (ret) {
+               pr_err("failed to set field value for perf_callchain_size\n");
+               goto put_len_field;
+       }
+       ret = bt_ctf_event_set_payload(event, "perf_callchain_size", len_field);
+       if (ret) {
+               pr_err("failed to set payload to perf_callchain_size\n");
+               goto put_len_field;
+       }
+
+       seq_type = bt_ctf_event_class_get_field_by_name(
+                       event_class, "perf_callchain");
+       seq_field = bt_ctf_field_create(seq_type);
+       if (!seq_field) {
+               pr_err("failed to create 'perf_callchain' for callchain output event\n");
+               ret = -1;
+               goto put_seq_type;
+       }
+
+       ret = bt_ctf_field_sequence_set_length(seq_field, len_field);
+       if (ret) {
+               pr_err("failed to set length of 'perf_callchain'\n");
+               goto put_seq_field;
+       }
+
+       for (i = 0; i < nr_elements; i++) {
+               struct bt_ctf_field *elem_field =
+                       bt_ctf_field_sequence_get_field(seq_field, i);
+
+               ret = bt_ctf_field_unsigned_integer_set_value(elem_field,
+                               ((u64 *)(callchain->ips))[i]);
+
+               bt_ctf_field_put(elem_field);
+               if (ret) {
+                       pr_err("failed to set callchain[%d]\n", i);
+                       goto put_seq_field;
+               }
+       }
+
+       ret = bt_ctf_event_set_payload(event, "perf_callchain", seq_field);
+       if (ret)
+               pr_err("failed to set payload for raw_data\n");
+
+put_seq_field:
+       bt_ctf_field_put(seq_field);
+put_seq_type:
+       bt_ctf_field_type_put(seq_type);
+put_len_field:
+       bt_ctf_field_put(len_field);
+put_len_type:
+       bt_ctf_field_type_put(len_type);
+       return ret;
+}
+
 static int add_generic_values(struct ctf_writer *cw,
                              struct bt_ctf_event *event,
                              struct perf_evsel *evsel,
@@ -519,7 +594,6 @@ static int add_generic_values(struct ctf_writer *cw,
         *   PERF_SAMPLE_TIME         - not needed as we have it in
         *                              ctf event header
         *   PERF_SAMPLE_READ         - TODO
-        *   PERF_SAMPLE_CALLCHAIN    - TODO
         *   PERF_SAMPLE_RAW          - tracepoint fields are handled separately
         *   PERF_SAMPLE_BRANCH_STACK - TODO
         *   PERF_SAMPLE_REGS_USER    - TODO
@@ -720,6 +794,7 @@ static int process_sample_event(struct perf_tool *tool,
        struct bt_ctf_event_class *event_class;
        struct bt_ctf_event *event;
        int ret;
+       unsigned long type = evsel->attr.sample_type;
 
        if (WARN_ONCE(!priv, "Failed to setup all events.\n"))
                return 0;
@@ -751,6 +826,13 @@ static int process_sample_event(struct perf_tool *tool,
                        return -1;
        }
 
+       if (type & PERF_SAMPLE_CALLCHAIN) {
+               ret = add_callchain_output_values(event_class,
+                               event, sample->callchain);
+               if (ret)
+                       return -1;
+       }
+
        if (perf_evsel__is_bpf_output(evsel)) {
                ret = add_bpf_output_values(event_class, event, sample);
                if (ret)
@@ -1043,6 +1125,14 @@ static int add_generic_types(struct ctf_writer *cw, struct perf_evsel *evsel,
        if (type & PERF_SAMPLE_TRANSACTION)
                ADD_FIELD(event_class, cw->data.u64, "perf_transaction");
 
+       if (type & PERF_SAMPLE_CALLCHAIN) {
+               ADD_FIELD(event_class, cw->data.u32, "perf_callchain_size");
+               ADD_FIELD(event_class,
+                       bt_ctf_field_type_sequence_create(
+                               cw->data.u64_hex, "perf_callchain_size"),
+                       "perf_callchain");
+       }
+
 #undef ADD_FIELD
        return 0;
 }