[RFC PATCH V2 8/9] perf evsel, tsc: Support the monotonic raw clock conversion

kan.liang
2023-02-13T19:08:33Z

From: Kan Liang <kan.liang@linux.intel.com>

The cap_user_time_mono_raw indicates that the kernel relies on the perf
tool to convert the HW time to the monotonic raw clock.
Add tsc_to_monotonic_raw() to do the conversion.

The conversion information is stored in the session, which cannot be
read in evsel parsing. Add a pointor in the evlist to point to the
conversion information.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
tools/perf/util/evlist.h | 1 +
tools/perf/util/evsel.c | 17 +++++++++++++++--
tools/perf/util/evsel.h | 7 +++++++
tools/perf/util/session.c | 1 +
tools/perf/util/tsc.c | 12 ++++++++++++
tools/perf/util/tsc.h | 2 ++
6 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 01fa9d592c5a..d860dc94009c 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -82,6 +82,7 @@ struct evlist {
int pos; /* index at evlist core object to check signals */
} ctl_fd;
struct event_enable_timer *eet;
+ struct perf_record_time_conv *time_conv;
};

struct evsel_str_handler {
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 999dd1700502..5e27ac2b9f9b 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -50,6 +50,7 @@
#include "off_cpu.h"
#include "../perf-sys.h"
#include "util/parse-branch-options.h"
+#include "tsc.h"
#include <internal/xyarray.h>
#include <internal/lib.h>
#include <internal/threadmap.h>
@@ -2349,6 +2350,18 @@ u64 evsel__bitfield_swap_branch_flags(u64 value)
return new_val;
}

+static u64 perf_evsel_parse_time(struct evsel *evsel, u64 time)
+{
+ /*
+ * The HW time can only be generated by HW events.
+ */
+ if ((evsel->core.attr.clockid == CLOCK_MONOTONIC_RAW) &&
+ evsel->evlist->time_conv && evsel__is_hw_event(evsel))
+ return tsc_to_monotonic_raw(evsel->evlist->time_conv, time);
+
+ return time;
+}
+
int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
struct perf_sample *data)
{
@@ -2411,7 +2424,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
}

if (type & PERF_SAMPLE_TIME) {
- data->time = *array;
+ data->time = perf_evsel_parse_time(evsel, *array);
array++;
}

@@ -2734,7 +2747,7 @@ int evsel__parse_sample_timestamp(struct evsel *evsel, union perf_event *event,
array++;

if (type & PERF_SAMPLE_TIME)
- *timestamp = *array;
+ *timestamp = perf_evsel_parse_time(evsel, *array);

return 0;
}
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index d572be41b960..d1ef67852bda 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -269,6 +269,13 @@ static inline bool evsel__is_bpf(struct evsel *evsel)
return evsel->bpf_counter_ops != NULL;
}

+static inline bool evsel__is_hw_event(struct evsel *evsel)
+{
+ return (evsel->core.attr.type == PERF_TYPE_HARDWARE) ||
+ (evsel->core.attr.type == PERF_TYPE_HW_CACHE) ||
+ (evsel->core.attr.type == PERF_TYPE_RAW);
+}
+
#define EVSEL__MAX_ALIASES 8

extern const char *const evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX][EVSEL__MAX_ALIASES];
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 189149a7012f..d80d0c4e46da 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1725,6 +1725,7 @@ static s64 perf_session__process_user_event(struct perf_session *session,
return tool->stat_round(session, event);
case PERF_RECORD_TIME_CONV:
session->time_conv = event->time_conv;
+ session->evlist->time_conv = &session->time_conv;
return tool->time_conv(session, event);
case PERF_RECORD_HEADER_FEATURE:
return tool->feature(session, event);
diff --git a/tools/perf/util/tsc.c b/tools/perf/util/tsc.c
index 0b59c0f815f9..5264f9d54be4 100644
--- a/tools/perf/util/tsc.c
+++ b/tools/perf/util/tsc.c
@@ -160,3 +160,15 @@ size_t perf_event__fprintf_time_conv(union perf_event *event, FILE *fp)

return ret;
}
+
+u64 tsc_to_monotonic_raw(struct perf_record_time_conv *tc, u64 cyc)
+{
+ u64 delta;
+
+ if (!tc->cap_user_time_mono_raw)
+ return cyc;
+
+ delta = (cyc - tc->time_mono_last) * tc->time_mono_mult + tc->time_mono_nsec;
+ delta >>= tc->time_mono_shift;
+ return tc->time_mono_base + delta;
+}
diff --git a/tools/perf/util/tsc.h b/tools/perf/util/tsc.h
index 6bacc450a14d..2611d3de94b1 100644
--- a/tools/perf/util/tsc.h
+++ b/tools/perf/util/tsc.h
@@ -35,4 +35,6 @@ double arch_get_tsc_freq(void);

size_t perf_event__fprintf_time_conv(union perf_event *event, FILE *fp);

+u64 tsc_to_monotonic_raw(struct perf_record_time_conv *tc, u64 cyc);
+
#endif // __PERF_TSC_H
--
2.35.1