From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v31 16/16] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file
Date: Thu, 11 Mar 2021 10:48:57 +0200 [thread overview]
Message-ID: <20210311084857.1919805-17-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20210311084857.1919805-1-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 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;
}
/*
--
2.29.2
prev parent reply other threads:[~2021-03-11 8:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 8:48 [PATCH v31 00/16] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 01/16] trace-cmd: Add timestamp synchronization per vCPU Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 02/16] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 03/16] trace-cmd: Move time sync logic in the trace-cmd library Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 04/16] trace-cmd: Wait for first time sync before the trace Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 05/16] trace-cmd: PTP-like algorithm for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 06/16] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 07/16] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 08/16] trace-cmd: Add initial perf interface in trace-cmd library Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 09/16] trace-cmd: Add logic for TSC to nanosecond conversion Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 10/16] trace-cmd: Append new options into guest trace file at the end of the tracing session Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 11/16] trace-cmd: Add a new option in trace file metadata for tsc2nsec conversion Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 12/16] trace-cmd: Save information for tsc to nanoseconds conversion in trace file Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 13/16] trace-cmd: Read information for tsc to nanoseconds conversion from " Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 14/16] trace-cmd: Remove unneeded multiply in events timestamp reading Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 15/16] trace-cmd: Perform all timestamp corrections in a single function Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` Tzvetomir Stoyanov (VMware) [this message]
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