| Message ID | 20210322095945.259300-13-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | TSC trace clock to nanosecond conversion | expand |
On Mon, 22 Mar 2021 11:59:39 +0200 "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > @@ -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; > } > Like I said, I like to save on extra variables ;-) static unsigned long long timestamp_calc(unsigned long long ts, struct tracecmd_input *handle) { ts = timestamp_correct(ts, handle); if (handle->ts2secs) ts *= handle->ts2secs; else if (handle->tsc_calc.mult) { ts -= handle->tsc_calc.offset; ts = mul_u64_u32_shr(t, handle->tsc_calc.mult, handle->tsc_calc.shift); } return ts; } -- Steve
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; } /*
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(-)