diff mbox series

[v31,16/16] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file

Message ID 20210311084857.1919805-17-tz.stoyanov@gmail.com (mailing list archive)
State Superseded
Headers show
Series Timestamp synchronization of host - guest tracing session | expand

Commit Message

Tzvetomir Stoyanov (VMware) March 11, 2021, 8:48 a.m. UTC 
If there is information for TSC to nanoseconds conversion in the trace
file metadata, use it to recalculate the timestamps of all events.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-input.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 60a59873..66483cc8 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -1287,17 +1287,37 @@  static unsigned long long timestamp_correct(unsigned long long ts, int cpu,
 					 &tsync->ts_samples[mid+1]);
 }
 
+static unsigned long long mul_u64_u32_shr(unsigned long long a,
+					  unsigned long long mul, unsigned int shift)
+{
+	unsigned int ah, al;
+	unsigned long long ret;
+
+	al = a;
+	ah = a >> 32;
+
+	ret = (al * mul) >> shift;
+	if (ah)
+		ret += (ah * mul) << (32 - shift);
+
+	return ret;
+}
+
 static unsigned long long timestamp_calc(unsigned long long ts, int cpu,
 					 struct tracecmd_input *handle)
 {
-	unsigned long long tstamp;
+	unsigned long long t;
 
-	tstamp = timestamp_correct(ts, cpu, handle);
+	t = timestamp_correct(ts, cpu, handle);
 
 	if (handle->ts2secs)
-		tstamp *= handle->ts2secs;
+		t *= handle->ts2secs;
+	else if (handle->tsc_calc.mult) {
+		t = mul_u64_u32_shr(t, handle->tsc_calc.mult, handle->tsc_calc.shift);
+		t += handle->tsc_calc.offset;
+	}
 
-	return tstamp;
+	return t;
 }
 
 /*