Re: [RFC][PATCH 03/21] ring-buffer: Add TIME_EXTEND_ABS ring buffer type

Tom Zanussi
2017-02-08T20:56:13Z

On Wed, 2017-02-08 at 15:32 -0500, Steven Rostedt wrote:
> On Wed, 8 Feb 2017 11:24:59 -0600
> Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
>
...
> > /*
> > * The event first in the commit queue updates the
> > * time stamp.
> > @@ -2492,8 +2516,7 @@ static inline void rb_event_discard(struct ring_buffer_event *event)
> > delta <<= TS_SHIFT;
> > delta += event->time_delta;
> > cpu_buffer->write_stamp += delta;
> > - } else
> > - cpu_buffer->write_stamp += event->time_delta;
> > + }
>
> And why is this removed?
>

Yeah, it doesn't make sense, given that we've returned already. Looks
like it was just a lineo..

> > }
> > }
> >
> > @@ -2674,7 +2697,7 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
> > * If this is the first commit on the page, then it has the same
> > * timestamp as the page itself.
> > */
> > - if (!tail)
> > + if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer))
> > info->delta = 0;
> >
> > /* See if we shot pass the end of this buffer page */
> > @@ -2752,8 +2775,11 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
> > /* make sure this diff is calculated here */
> > barrier();
> >
> > - /* Did the write stamp get updated already? */
> > - if (likely(info.ts >= cpu_buffer->write_stamp)) {
> > + if (ring_buffer_time_stamp_abs(buffer)) {
> > + info.delta = info.ts;
> > + rb_handle_timestamp(cpu_buffer, &info);
> > + } else /* Did the write stamp get updated already? */
> > + if (likely(info.ts >= cpu_buffer->write_stamp)) {
>
> OK, please break this patch up into two. Although, I may take it and
> start on it as well ;-) One with the implementation of the EXTEND_ABS,
> and the other with the setting of the flags.
>

OK, I'll break it up if I don't see you do anything with it in the
meantime..

Tom