On Fri, Mar 19, 2021 at 05:15:35AM +0100, Willy Tarreau wrote:
> On Fri, Mar 19, 2021 at 12:04:47PM +0800, Sieng Piaw Liew wrote:
> > Remove this trivial bit of inefficiency from the rx receive loop,
> > results in increase of a few Mbps in iperf3. Tested on Intel Core2
> > platform.
> >
> > Signed-off-by: Sieng Piaw Liew <liew.s.p...@gmail.com>
> > ---
> > drivers/net/ethernet/atheros/atl1c/atl1c_main.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > index 3f65f2b370c5..b995f9a0479c 100644
> > --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > @@ -1796,9 +1796,7 @@ static void atl1c_clean_rx_irq(struct atl1c_adapter
> > *adapter,
> > struct atl1c_recv_ret_status *rrs;
> > struct atl1c_buffer *buffer_info;
> >
> > - while (1) {
> > - if (*work_done >= work_to_do)
> > - break;
> > + while (*work_done < work_to_do) {
>
> It should not change anything, or only based on the compiler's optimization
> and should not result in a measurable difference because what it does is
> exactly the same. Have you really compared the compiled output code to
> explain the difference ? I strongly suspect you'll find no difference at
> all.
>
> Thus for me it's certainly not an optimization, it could be qualified as
> a cleanup to improve code readability however.
>
> Willy
You're right. Objdump and diff showed no difference.
Regards,
Sieng Piaw
