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Subject[PATCH v3 4/6] perf tsc: Support cap_user_time_short for event TIME_CONV
Date
The synthesized event TIME_CONV doesn't contain the complete parameters
for counters, this will lead to wrong conversion between counter cycles
and timestamp.

This patch extends event TIME_CONV to record flags 'cap_user_time_zero'
which is used to indicate the counter parameters are valid or not, if
not will directly return 0 for timestamp calculation. And record the
flag 'cap_user_time_short' and its relevant fields 'time_cycles' and
'time_mask' for cycle calibration.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
tools/lib/perf/include/perf/event.h | 4 ++++
tools/perf/util/jitdump.c | 14 +++++++++-----
tools/perf/util/tsc.c | 4 ++++
3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index 842028858d66..a6dbba6b9073 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -324,6 +324,10 @@ struct perf_record_time_conv {
__u64 time_shift;
__u64 time_mult;
__u64 time_zero;
+ __u64 time_cycles;
+ __u64 time_mask;
+ bool cap_user_time_zero;
+ bool cap_user_time_short;
};

struct perf_record_header_feature {
diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
index 0804308ef285..055bab7a92b3 100644
--- a/tools/perf/util/jitdump.c
+++ b/tools/perf/util/jitdump.c
@@ -374,11 +374,15 @@ static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp)
if (!jd->use_arch_timestamp)
return timestamp;

- tc.time_shift = jd->session->time_conv.time_shift;
- tc.time_mult = jd->session->time_conv.time_mult;
- tc.time_zero = jd->session->time_conv.time_zero;
-
- if (!tc.time_mult)
+ tc.time_shift = jd->session->time_conv.time_shift;
+ tc.time_mult = jd->session->time_conv.time_mult;
+ tc.time_zero = jd->session->time_conv.time_zero;
+ tc.time_cycles = jd->session->time_conv.time_cycles;
+ tc.time_mask = jd->session->time_conv.time_mask;
+ tc.cap_user_time_zero = jd->session->time_conv.cap_user_time_zero;
+ tc.cap_user_time_short = jd->session->time_conv.cap_user_time_short;
+
+ if (!tc.cap_user_time_zero)
return 0;

return tsc_to_perf_time(timestamp, &tc);
diff --git a/tools/perf/util/tsc.c b/tools/perf/util/tsc.c
index c0ca40204649..62b4c75c966c 100644
--- a/tools/perf/util/tsc.c
+++ b/tools/perf/util/tsc.c
@@ -98,6 +98,10 @@ int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
event.time_conv.time_mult = tc.time_mult;
event.time_conv.time_shift = tc.time_shift;
event.time_conv.time_zero = tc.time_zero;
+ event.time_conv.time_cycles = tc.time_cycles;
+ event.time_conv.time_mask = tc.time_mask;
+ event.time_conv.cap_user_time_zero = tc.cap_user_time_zero;
+ event.time_conv.cap_user_time_short = tc.cap_user_time_short;

return process(tool, &event, NULL, machine);
}
--
2.17.1
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