perf record: Encode -k clockid frequency into Perf trace

Store -k clockid frequency into Perf trace to enable timestamps
derived metrics conversion into wall clock time on reporting stage.

Below is the example of perf report output:

  tools/perf/perf record -k raw -- ../../matrix/linux/matrix.gcc
  ...
  [ perf record: Captured and wrote 31.222 MB perf.data (818054 samples) ]

  tools/perf/perf report --header
  # ========
  ...
  # event : name = cycles:ppp, , size = 112, { sample_period, sample_freq } = 4000, sample_type = IP|TID|TIME|PERIOD, disabled = 1, inherit = 1, mmap = 1, comm = 1, freq = 1, enable_on_exec = 1, task = 1, precise_ip = 3, sample_id_all = 1, exclude_guest = 1, mmap2 = 1, comm_exec = 1, use_clockid = 1, clockid = 4
  ...
  # clockid frequency: 1000 MHz
  ...
  # ========

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/23a4a1dc-b160-85a0-347d-40a2ed6d007b@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0980dfe3396b188c3dd5692ad673bae137cb357c..10cf889c6d75d2db1d78014215e30948ae3b1cb4 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -592,6 +592,9 @@ static void record__init_features(struct record *rec)
        if (!rec->opts.full_auxtrace)
                perf_header__clear_feat(&session->header, HEADER_AUXTRACE);
 
+       if (!(rec->opts.use_clockid && rec->opts.clockid_res_ns))
+               perf_header__clear_feat(&session->header, HEADER_CLOCKID);
+
        perf_header__clear_feat(&session->header, HEADER_STAT);
 }
 
@@ -897,6 +900,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
        record__init_features(rec);
 
+       if (rec->opts.use_clockid && rec->opts.clockid_res_ns)
+               session->header.env.clockid_res_ns = rec->opts.clockid_res_ns;
+
        if (forks) {
                err = perf_evlist__prepare_workload(rec->evlist, &opts->target,
                                                    argv, data->is_pipe,
@@ -1337,6 +1343,19 @@ static const struct clockid_map clockids[] = {
        CLOCKID_END,
 };
 
+static int get_clockid_res(clockid_t clk_id, u64 *res_ns)
+{
+       struct timespec res;
+
+       *res_ns = 0;
+       if (!clock_getres(clk_id, &res))
+               *res_ns = res.tv_nsec + res.tv_sec * NSEC_PER_SEC;
+       else
+               pr_warning("WARNING: Failed to determine specified clock resolution.\n");
+
+       return 0;
+}
+
 static int parse_clockid(const struct option *opt, const char *str, int unset)
 {
        struct record_opts *opts = (struct record_opts *)opt->value;
@@ -1360,7 +1379,7 @@ static int parse_clockid(const struct option *opt, const char *str, int unset)
 
        /* if its a number, we're done */
        if (sscanf(str, "%d", &opts->clockid) == 1)
-               return 0;
+               return get_clockid_res(opts->clockid, &opts->clockid_res_ns);
 
        /* allow a "CLOCK_" prefix to the name */
        if (!strncasecmp(str, "CLOCK_", 6))
@@ -1369,7 +1388,8 @@ static int parse_clockid(const struct option *opt, const char *str, int unset)
        for (cm = clockids; cm->name; cm++) {
                if (!strcasecmp(str, cm->name)) {
                        opts->clockid = cm->clockid;
-                       return 0;
+                       return get_clockid_res(opts->clockid,
+                                              &opts->clockid_res_ns);
                }
        }
 

diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 21bf7f5a3cf51a1a42e3169daa738c8e7e0a8d83..0ed4a34c74c4bc6d2c38457c05a59dd9f6ea8551 100644 (file)
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -81,6 +81,7 @@ struct record_opts {
        unsigned     initial_delay;
        bool         use_clockid;
        clockid_t    clockid;
+       u64          clockid_res_ns;
        unsigned int proc_map_timeout;
 };
 

diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 1f3ccc36853030bc8ea58d35ea19bba8e225f732..d01b8355f4caba9440d0e0d4db4c6f241e801dc7 100644 (file)
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -63,6 +63,7 @@ struct perf_env {
        struct numa_node        *numa_nodes;
        struct memory_node      *memory_nodes;
        unsigned long long       memory_bsize;
+       u64                     clockid_res_ns;
 };
 
 extern struct perf_env perf_env;

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 1ec1d9bc2d6356bf98d053aec68331c21142907a..4fd45be95a433e32ac8839dd6f9b402be6d34b00 100644 (file)
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1034,6 +1034,13 @@ static int write_auxtrace(struct feat_fd *ff,
        return err;
 }
 
+static int write_clockid(struct feat_fd *ff,
+                        struct perf_evlist *evlist __maybe_unused)
+{
+       return do_write(ff, &ff->ph->env.clockid_res_ns,
+                       sizeof(ff->ph->env.clockid_res_ns));
+}
+
 static int cpu_cache_level__sort(const void *a, const void *b)
 {
        struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
@@ -1508,6 +1515,12 @@ static void print_cpu_topology(struct feat_fd *ff, FILE *fp)
                fprintf(fp, "# Core ID and Socket ID information is not available\n");
 }
 
+static void print_clockid(struct feat_fd *ff, FILE *fp)
+{
+       fprintf(fp, "# clockid frequency: %"PRIu64" MHz\n",
+               ff->ph->env.clockid_res_ns * 1000);
+}
+
 static void free_event_desc(struct perf_evsel *events)
 {
        struct perf_evsel *evsel;
@@ -2531,6 +2544,15 @@ out:
        return ret;
 }
 
+static int process_clockid(struct feat_fd *ff,
+                          void *data __maybe_unused)
+{
+       if (do_read_u64(ff, &ff->ph->env.clockid_res_ns))
+               return -1;
+
+       return 0;
+}
+
 struct feature_ops {
        int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
        void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2590,6 +2612,7 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
        FEAT_OPN(CACHE,         cache,          true),
        FEAT_OPR(SAMPLE_TIME,   sample_time,    false),
        FEAT_OPR(MEM_TOPOLOGY,  mem_topology,   true),
+       FEAT_OPR(CLOCKID,       clockid,        false)
 };
 
 struct header_print_data {

diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index e17903caa71daba074fbaaf04252525beac2df11..0d553ddca0a3049f941d96a0ae0d68b71ea7a49c 100644 (file)
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -38,6 +38,7 @@ enum {
        HEADER_CACHE,
        HEADER_SAMPLE_TIME,
        HEADER_MEM_TOPOLOGY,
+       HEADER_CLOCKID,
        HEADER_LAST_FEATURE,
        HEADER_FEAT_BITS        = 256,
 };