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From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v2 12/18] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file
Date: Mon, 22 Mar 2021 11:59:39 +0200	[thread overview]
Message-ID: <20210322095945.259300-13-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20210322095945.259300-1-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 | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index dfbe4af6..7ac81809 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -1196,6 +1196,23 @@ static void free_next(struct tracecmd_input *handle, int cpu)
 	tracecmd_free_record(record);
 }
 
+/* This functions was taken from the Linux kernel */
+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 inline unsigned long long
 timestamp_correction_calc(unsigned long long ts, unsigned int flags,
 			  struct ts_offset_sample *min,
@@ -1279,14 +1296,18 @@ static unsigned long long timestamp_correct(unsigned long long ts,
 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 -= handle->tsc_calc.offset;
+		t = mul_u64_u32_shr(t, handle->tsc_calc.mult, handle->tsc_calc.shift);
+	}
 
-	return tstamp;
+	return t;
 }
 
 /*
-- 
2.30.2


  parent reply	other threads:[~2021-03-22 10:01 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22  9:59 [PATCH v2 00/18] TSC trace clock to nanosecond conversion Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 01/18] trace-cmd: Add initial perf interface in trace-cmd library Tzvetomir Stoyanov (VMware)
2021-03-24  0:47   ` Steven Rostedt
2021-03-22  9:59 ` [PATCH v2 02/18] trace-cmd: Extend trace-cmd dump subcommand to display the clock Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 03/18] trace-cmd: Save only the selected clock in the trace.dat file Tzvetomir Stoyanov (VMware)
2021-03-24  0:52   ` Steven Rostedt
2021-03-24  9:10     ` Tzvetomir Stoyanov
2021-03-22  9:59 ` [PATCH v2 04/18] trace-cmd: Add new trace-cmd clock tsc2nsec Tzvetomir Stoyanov (VMware)
2021-03-24  1:24   ` Steven Rostedt
2021-03-22  9:59 ` [PATCH v2 05/18] trace-cmd: Add a new option in trace file metadata for tsc2nsec conversion Tzvetomir Stoyanov (VMware)
2021-03-24  1:26   ` Steven Rostedt
2021-03-22  9:59 ` [PATCH v2 06/18] trace-cmd: Save information for tsc to nanoseconds conversion in trace file Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 07/18] trace-cmd: Read information for tsc to nanoseconds conversion from " Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 08/18] trace-cmd: Save tsc2nsec clock in trace.dat file Tzvetomir Stoyanov (VMware)
2021-03-24  1:33   ` Steven Rostedt
2021-03-24  4:58     ` Tzvetomir Stoyanov
2021-03-22  9:59 ` [PATCH v2 09/18] trace-cmd: Append new options into guest trace file at the end of the tracing session Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 10/18] trace-cmd: Remove unneeded multiply in events timestamp reading Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 11/18] trace-cmd: Perform all timestamp corrections in a single function Tzvetomir Stoyanov (VMware)
2021-03-24  1:38   ` Steven Rostedt
2021-03-22  9:59 ` Tzvetomir Stoyanov (VMware) [this message]
2021-03-24  1:41   ` [PATCH v2 12/18] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file Steven Rostedt
2021-03-22  9:59 ` [PATCH v2 13/18] trace-cmd: Set order and priorities when applying timestamp corrections Tzvetomir Stoyanov (VMware)
2021-03-24  1:44   ` Steven Rostedt
2021-03-22  9:59 ` [PATCH v2 14/18] trace-cmd: Add a new flag to disable any " Tzvetomir Stoyanov (VMware)
2021-03-24  1:49   ` Steven Rostedt
2021-03-24 12:10     ` Tzvetomir Stoyanov
2021-03-24 12:15       ` Steven Rostedt
2021-03-22  9:59 ` [PATCH v2 15/18] trace-cmd: Add new parameter "--raw-ts" to "trace-cmd report" command Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 16/18] trace-cmd: Print times in TimeShift options as unsigned in trace-cmd dump Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 17/18] trace-cmd: Use tsc clock for host-guest tracing, if available Tzvetomir Stoyanov (VMware)
2021-03-22  9:59 ` [PATCH v2 18/18] trace-cmd: Get current clock for host-guest tracing session Tzvetomir Stoyanov (VMware)
2021-03-24  1:52   ` Steven Rostedt

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