[PATCH V2 04/11] perf tools: Add new perf clock IDs

[Adrian Hunter <adrian.hunter@intel.com>]

Add support for new clock IDs CLOCK_PERF_HW_CLOCK and
CLOCK_PERF_HW_CLOCK_NS.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/include/uapi/linux/perf_event.h     | 18 +++++++++++++++++-
 tools/perf/Documentation/perf-record.txt  |  9 ++++++++-
 tools/perf/builtin-record.c               |  2 +-
 tools/perf/util/clockid.c                 | 13 +++++++++++++
 tools/perf/util/evsel.c                   |  1 +
 tools/perf/util/perf_event_attr_fprintf.c |  1 +
 tools/perf/util/record.h                  |  1 +
 7 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 1b65042ab1db..7b3455dfda23 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -290,6 +290,21 @@ enum {
 	PERF_TXN_ABORT_SHIFT = 32,
 };
 
+/*
+ * If supported, clockid value to select an architecture dependent hardware
+ * clock. Note this means the unit of time is ticks not nanoseconds.
+ * Requires ns_clockid to be set in addition to use_clockid.
+ * On x86, this clock is provided by the rdtsc instruction, and is not
+ * paravirtualized.
+ */
+#define CLOCK_PERF_HW_CLOCK		0x10000000
+/*
+ * Same as CLOCK_PERF_HW_CLOCK but in nanoseconds. Note support of
+ * CLOCK_PERF_HW_CLOCK_NS does not necesssarily imply support of
+ * CLOCK_PERF_HW_CLOCK or vice versa.
+ */
+#define CLOCK_PERF_HW_CLOCK_NS	0x10000001
+
 /*
  * The format of the data returned by read() on a perf event fd,
  * as specified by attr.read_format:
@@ -409,7 +424,8 @@ struct perf_event_attr {
 				inherit_thread :  1, /* children only inherit if cloned with CLONE_THREAD */
 				remove_on_exec :  1, /* event is removed from task on exec */
 				sigtrap        :  1, /* send synchronous SIGTRAP on event */
-				__reserved_1   : 26;
+				ns_clockid     :  1, /* non-standard clockid */
+				__reserved_1   : 25;
 
 	union {
 		__u32		wakeup_events;	  /* wakeup every n events */
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 9ccc75935bc5..a5ef4813093a 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -444,7 +444,14 @@ Record running and enabled time for read events (:S)
 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.
+CLOCK_BOOTTIME, CLOCK_REALTIME and CLOCK_TAI. In addition, the kernel might
+support CLOCK_PERF_HW_CLOCK to select an architecture dependent hardware
+clock, for which the unit of time is ticks not nanoseconds. On x86,
+CLOCK_PERF_HW_CLOCK is provided by the rdtsc instruction, and is not
+paravirtualized. There is also CLOCK_PERF_HW_CLOCK_NS which is the same as
+CLOCK_PERF_HW_CLOCK, but converted to nanoseconds. Note support of
+CLOCK_PERF_HW_CLOCK_NS does not necessarily imply support of
+CLOCK_PERF_HW_CLOCK or vice versa.
 
 -S::
 --snapshot::
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index bb716c953d02..febb51bac6ac 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1553,7 +1553,7 @@ static int record__init_clock(struct record *rec)
 	struct timeval ref_tod;
 	u64 ref;
 
-	if (!rec->opts.use_clockid)
+	if (!rec->opts.use_clockid || rec->opts.ns_clockid)
 		return 0;
 
 	if (rec->opts.use_clockid && rec->opts.clockid_res_ns)
diff --git a/tools/perf/util/clockid.c b/tools/perf/util/clockid.c
index 74365a5d99c1..2fcffee690e1 100644
--- a/tools/perf/util/clockid.c
+++ b/tools/perf/util/clockid.c
@@ -12,11 +12,15 @@
 struct clockid_map {
 	const char *name;
 	int clockid;
+	bool non_standard;
 };
 
 #define CLOCKID_MAP(n, c)	\
 	{ .name = n, .clockid = (c), }
 
+#define CLOCKID_MAP_NS(n, c)	\
+	{ .name = n, .clockid = (c), .non_standard = true, }
+
 #define CLOCKID_END	{ .name = NULL, }
 
 
@@ -49,6 +53,10 @@ static const struct clockid_map clockids[] = {
 	CLOCKID_MAP("real", CLOCK_REALTIME),
 	CLOCKID_MAP("boot", CLOCK_BOOTTIME),
 
+	/* non-standard clocks */
+	CLOCKID_MAP_NS("perf_hw_clock", CLOCK_PERF_HW_CLOCK),
+	CLOCKID_MAP_NS("perf_hw_clock_ns", CLOCK_PERF_HW_CLOCK_NS),
+
 	CLOCKID_END,
 };
 
@@ -97,6 +105,11 @@ 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;
+			if (cm->non_standard) {
+				opts->ns_clockid = true;
+				opts->clockid_res_ns = 0;
+				return 0;
+			}
 			return get_clockid_res(opts->clockid,
 					       &opts->clockid_res_ns);
 		}
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 22d3267ce294..be1d30490a43 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1294,6 +1294,7 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
 	clockid = opts->clockid;
 	if (opts->use_clockid) {
 		attr->use_clockid = 1;
+		attr->ns_clockid = opts->ns_clockid;
 		attr->clockid = opts->clockid;
 	}
 
diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
index 98af3fa4ea35..398f05f2e5b3 100644
--- a/tools/perf/util/perf_event_attr_fprintf.c
+++ b/tools/perf/util/perf_event_attr_fprintf.c
@@ -128,6 +128,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
 	PRINT_ATTRf(mmap2, p_unsigned);
 	PRINT_ATTRf(comm_exec, p_unsigned);
 	PRINT_ATTRf(use_clockid, p_unsigned);
+	PRINT_ATTRf(ns_clockid, p_unsigned);
 	PRINT_ATTRf(context_switch, p_unsigned);
 	PRINT_ATTRf(write_backward, p_unsigned);
 	PRINT_ATTRf(namespaces, p_unsigned);
diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h
index ef6c2715fdd9..1dbbf6b314dc 100644
--- a/tools/perf/util/record.h
+++ b/tools/perf/util/record.h
@@ -67,6 +67,7 @@ struct record_opts {
 	bool	      sample_transaction;
 	int	      initial_delay;
 	bool	      use_clockid;
+	bool	      ns_clockid;
 	clockid_t     clockid;
 	u64	      clockid_res_ns;
 	int	      nr_cblocks;
-- 
2.25.1