On Sun, 28 Feb 2021 23:27:25 +0100
Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx> wrote:
> > > drops = bq->count - sent;
> > > -out:
> > > - bq->count = 0;
> > > + if (unlikely(drops > 0)) {
> > > + /* If not all frames have been transmitted, it is our
> > > + * responsibility to free them
> > > + */
> > > + for (i = sent; i < bq->count; i++)
> > > + xdp_return_frame_rx_napi(bq->q[i]);
> > > + }
> >
> > Wouldn't the logic above be the same even w/o the 'if' condition ?
>
> it is just an optimization to avoid the for loop instruction if sent = bq->count
True, and I like this optimization.
It will affect how the code layout is (and thereby I-cache usage).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
