On Thu, Dec 3, 2020 at 3:47 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Thu, 29 Oct 2020 13:18:09 +0200
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> > @@ -2181,7 +2184,9 @@ static void tsync_offset_load(struct tracecmd_input *handle, char *buf)
> > host->ts_samples[i].time = tep_read_number(handle->pevent,
> > buf8 + i, 8);
> > host->ts_samples[i].offset = tep_read_number(handle->pevent,
> > - buf8 + host->ts_samples_count+i, 8);
> > + buf8 + host->ts_samples_count + i, 8);
> > + host->ts_samples[i].scaling = tep_read_number(handle->pevent,
> > + buf8 + (2 * host->ts_samples_count) + i, 8);
> > }
>
>
> I was thinking the above code may read better if we changed it to:
>
> long long *time_buf;
> long long *offset_buf;
> long long *scaling_buf;
>
> time_buf = (long long *)buf;
> offset_buf = time_buf + host->ts_samples_count;
> scaling_buf = offset_buf + host->ts_samples_count;
>
> for (i = 0; i < host->ts_samples_count; i++) {
> host->ts_samples[i].time = tep_read_number(handle->pevent,
> time_buf + i, 8);
> host->ts_samples[i].offset = tep_read_number(handle-> pevent,
> offset_buf + i, 8);
> host->ts_samples[i].scaling = tep_read_number(handle->pevent,
> scaling_buf + i, 8);
> }
>
This code is rewritten in "trace-cmd: Add timestamp synchronization
per vCPU" patch
in a better and safer way.
> -- Steve
>
>
>
> > qsort(host->ts_samples, host->ts_samples_count,
> > sizeof(struct ts_offset_sample), tsync_offset_cmp);
> > @@ -2534,6 +2539,7 @@ static int handle_options(struct tracecmd_input *handle)
> > * long long array of size [count] of times,
> > * when the offsets were calculated.
> > * long long array of size [count] of timestamp offsets.
> > + * long long array of size [count] of timestamp scaling ratios.*
> > */
> > if (size < 12 || handle->flags & TRACECMD_FL_IGNORE_DATE)
> > break;
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
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