perf record: Add clockid parameter

Teach perf-record about the new perf_event_attr::{use_clockid, clockid}
fields. Add a simple parameter to set the clock (if any) to be used for
the events to be recorded into the data file.

Since we store the entire perf_event_attr in the EVENT_DESC section we
also already store the used clockid in the data file.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yunlong Song <yunlong.song@huawei.com>
Link: http://lkml.kernel.org/r/20150407154851.GR23123@twins.programming.kicks-ass.net
[ Conditionally define CLOCK_BOOTTIME, at least rhel6 doesn't have it - dsahern
  Ditto for CLOCK_MONOTONIC_RAW, sles11sp2 doesn't have it - yunlong.song ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

5 files changed, 154 insertions, 4 deletions

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 355c4f5569b5..4847a793de65 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -250,6 +250,13 @@ is off by default.
 --running-time::
 Record running and enabled time for read events (:S)
 
+-k::
+--clockid::
+Sets the clock id to use for the various time fields in the perf_event_type
+records. See clock_gettime(). In particular CLOCK_MONOTONIC and
+CLOCK_MONOTONIC_RAW are supported, some events might also allow
+CLOCK_BOOTTIME, CLOCK_REALTIME and CLOCK_TAI.
+
 SEE ALSO
 --------
 linkperf:perf-stat[1], linkperf:perf-list[1]
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 18aad239b401..ac610488d2e1 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -711,6 +711,90 @@ static int perf_record_config(const char *var, const char *value, void *cb)
         return perf_default_config(var, value, cb);
 }
 
+struct clockid_map {
+        const char *name;
+        int clockid;
+};
+
+#define CLOCKID_MAP(n, c)       \
+        { .name = n, .clockid = (c), }
+
+#define CLOCKID_END     { .name = NULL, }
+
+
+/*
+ * Add the missing ones, we need to build on many distros...
+ */
+#ifndef CLOCK_MONOTONIC_RAW
+#define CLOCK_MONOTONIC_RAW 4
+#endif
+#ifndef CLOCK_BOOTTIME
+#define CLOCK_BOOTTIME 7
+#endif
+#ifndef CLOCK_TAI
+#define CLOCK_TAI 11
+#endif
+
+static const struct clockid_map clockids[] = {
+        /* available for all events, NMI safe */
+        CLOCKID_MAP("monotonic", CLOCK_MONOTONIC),
+        CLOCKID_MAP("monotonic_raw", CLOCK_MONOTONIC_RAW),
+
+        /* available for some events */
+        CLOCKID_MAP("realtime", CLOCK_REALTIME),
+        CLOCKID_MAP("boottime", CLOCK_BOOTTIME),
+        CLOCKID_MAP("tai", CLOCK_TAI),
+
+        /* available for the lazy */
+        CLOCKID_MAP("mono", CLOCK_MONOTONIC),
+        CLOCKID_MAP("raw", CLOCK_MONOTONIC_RAW),
+        CLOCKID_MAP("real", CLOCK_REALTIME),
+        CLOCKID_MAP("boot", CLOCK_BOOTTIME),
+
+        CLOCKID_END,
+};
+
+static int parse_clockid(const struct option *opt, const char *str, int unset)
+{
+        struct record_opts *opts = (struct record_opts *)opt->value;
+        const struct clockid_map *cm;
+        const char *ostr = str;
+
+        if (unset) {
+                opts->use_clockid = 0;
+                return 0;
+        }
+
+        /* no arg passed */
+        if (!str)
+                return 0;
+
+        /* no setting it twice */
+        if (opts->use_clockid)
+                return -1;
+
+        opts->use_clockid = true;
+
+        /* if its a number, we're done */
+        if (sscanf(str, "%d", &opts->clockid) == 1)
+                return 0;
+
+        /* allow a "CLOCK_" prefix to the name */
+        if (!strncasecmp(str, "CLOCK_", 6))
+                str += 6;
+
+        for (cm = clockids; cm->name; cm++) {
+                if (!strcasecmp(str, cm->name)) {
+                        opts->clockid = cm->clockid;
+                        return 0;
+                }
+        }
+
+        opts->use_clockid = false;
+        ui__warning("unknown clockid %s, check man page\n", ostr);
+        return -1;
+}
+
 static const char * const __record_usage[] = {
         "perf record [<options>] [<command>]",
         "perf record [<options>] -- <command> [<options>]",
@@ -842,6 +926,9 @@ struct option __record_options[] = {
                     "Sample machine registers on interrupt"),
         OPT_BOOLEAN(0, "running-time", &record.opts.running_time,
                     "Record running/enabled time of read (:S) events"),
+        OPT_CALLBACK('k', "clockid", &record.opts,
+        "clockid", "clockid to use for events, see clock_gettime()",
+        parse_clockid),
         OPT_END()
 };
 
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index c38a085a5571..e14bb637255c 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -62,6 +62,8 @@ struct record_opts {
         u64          user_interval;
         bool         sample_transaction;
         unsigned     initial_delay;
+        bool         use_clockid;
+        clockid_t    clockid;
 };
 
 struct option;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 358e5954baa8..d190f99a3a97 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -32,8 +32,12 @@ static struct {
         bool exclude_guest;
         bool mmap2;
         bool cloexec;
+        bool clockid;
+        bool clockid_wrong;
 } perf_missing_features;
 
+static clockid_t clockid;
+
 static int perf_evsel__no_extra_init(struct perf_evsel *evsel __maybe_unused)
 {
         return 0;
@@ -761,6 +765,12 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
                 attr->disabled = 0;
                 attr->enable_on_exec = 0;
         }
+
+        clockid = opts->clockid;
+        if (opts->use_clockid) {
+                attr->use_clockid = 1;
+                attr->clockid = opts->clockid;
+        }
 }
 
 static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
@@ -1036,7 +1046,6 @@ static size_t perf_event_attr__fprintf(struct perf_event_attr *attr, FILE *fp)
         ret += PRINT_ATTR2(exclude_user, exclude_kernel);
         ret += PRINT_ATTR2(exclude_hv, exclude_idle);
         ret += PRINT_ATTR2(mmap, comm);
-        ret += PRINT_ATTR2(mmap2, comm_exec);
         ret += PRINT_ATTR2(freq, inherit_stat);
         ret += PRINT_ATTR2(enable_on_exec, task);
         ret += PRINT_ATTR2(watermark, precise_ip);
@@ -1044,6 +1053,9 @@ static size_t perf_event_attr__fprintf(struct perf_event_attr *attr, FILE *fp)
         ret += PRINT_ATTR2(exclude_host, exclude_guest);
         ret += PRINT_ATTR2N("excl.callchain_kern", exclude_callchain_kernel,
                             "excl.callchain_user", exclude_callchain_user);
+        ret += PRINT_ATTR2(mmap2, comm_exec);
+        ret += __PRINT_ATTR("%u",,use_clockid);
+
 
         ret += PRINT_ATTR_U32(wakeup_events);
         ret += PRINT_ATTR_U32(wakeup_watermark);
@@ -1055,6 +1067,7 @@ static size_t perf_event_attr__fprintf(struct perf_event_attr *attr, FILE *fp)
         ret += PRINT_ATTR_X64(branch_sample_type);
         ret += PRINT_ATTR_X64(sample_regs_user);
         ret += PRINT_ATTR_U32(sample_stack_user);
+        ret += PRINT_ATTR_U32(clockid);
         ret += PRINT_ATTR_X64(sample_regs_intr);
 
         ret += fprintf(fp, "%.60s\n", graph_dotted_line);
@@ -1085,6 +1098,12 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
         }
 
 fallback_missing_features:
+        if (perf_missing_features.clockid_wrong)
+                evsel->attr.clockid = CLOCK_MONOTONIC; /* should always work */
+        if (perf_missing_features.clockid) {
+                evsel->attr.use_clockid = 0;
+                evsel->attr.clockid = 0;
+        }
         if (perf_missing_features.cloexec)
                 flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC;
         if (perf_missing_features.mmap2)
@@ -1122,6 +1141,17 @@ retry_open:
                                 goto try_fallback;
                         }
                         set_rlimit = NO_CHANGE;
+
+                        /*
+                         * If we succeeded but had to kill clockid, fail and
+                         * have perf_evsel__open_strerror() print us a nice
+                         * error.
+                         */
+                        if (perf_missing_features.clockid ||
+                            perf_missing_features.clockid_wrong) {
+                                err = -EINVAL;
+                                goto out_close;
+                        }
                 }
         }
 
@@ -1155,7 +1185,17 @@ try_fallback:
         if (err != -EINVAL || cpu > 0 || thread > 0)
                 goto out_close;
 
-        if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
+        /*
+         * Must probe features in the order they were added to the
+         * perf_event_attr interface.
+         */
+        if (!perf_missing_features.clockid_wrong && evsel->attr.use_clockid) {
+                perf_missing_features.clockid_wrong = true;
+                goto fallback_missing_features;
+        } else if (!perf_missing_features.clockid && evsel->attr.use_clockid) {
+                perf_missing_features.clockid = true;
+                goto fallback_missing_features;
+        } else if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
                 perf_missing_features.cloexec = true;
                 goto fallback_missing_features;
         } else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
@@ -2063,9 +2103,7 @@ int perf_evsel__fprintf(struct perf_evsel *evsel,
                 if_print(exclude_hv);
                 if_print(exclude_idle);
                 if_print(mmap);
-                if_print(mmap2);
                 if_print(comm);
-                if_print(comm_exec);
                 if_print(freq);
                 if_print(inherit_stat);
                 if_print(enable_on_exec);
@@ -2076,10 +2114,17 @@ int perf_evsel__fprintf(struct perf_evsel *evsel,
                 if_print(sample_id_all);
                 if_print(exclude_host);
                 if_print(exclude_guest);
+                if_print(mmap2);
+                if_print(comm_exec);
+                if_print(use_clockid);
                 if_print(__reserved_1);
                 if_print(wakeup_events);
                 if_print(bp_type);
                 if_print(branch_sample_type);
+                if_print(sample_regs_user);
+                if_print(sample_stack_user);
+                if_print(clockid);
+                if_print(sample_regs_intr);
         }
 out:
         fputc('\n', fp);
@@ -2158,6 +2203,12 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
         "The PMU counters are busy/taken by another profiler.\n"
         "We found oprofile daemon running, please stop it and try again.");
                 break;
+        case EINVAL:
+                if (perf_missing_features.clockid)
+                        return scnprintf(msg, size, "clockid feature not supported.");
+                if (perf_missing_features.clockid_wrong)
+                        return scnprintf(msg, size, "wrong clockid (%d).", clockid);
+                break;
         default:
                 break;
         }
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index fb432153e2aa..de5f4669ba5f 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1098,6 +1098,9 @@ static void print_event_desc(struct perf_header *ph, int fd, FILE *fp)
                         }
                         fprintf(fp, " }");
                 }
+                if (evsel->attr.use_clockid)
+                        fprintf(fp, ", clockid = %d", evsel->attr.clockid);
+
 
                 fputc('\n', fp);
         }