[PATCH 09/12] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file

From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH 09/12] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file
Date: Mon, 15 Mar 2021 08:18:29 +0200	[thread overview]
Message-ID: <20210315061832.168495-10-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20210315061832.168495-1-tz.stoyanov@gmail.com>

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 --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 65081007..dc9ac1d3 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -1276,17 +1276,37 @@ static unsigned long long timestamp_correct(unsigned long long ts,
 					 &host->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,
 					 struct tracecmd_input *handle)
 {
-	unsigned long long tstamp;
+	unsigned long long t;
 
-	tstamp = timestamp_correct(ts, handle);
+	t = timestamp_correct(ts, 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;
 }
 
 /*
-- 
2.29.2

