Re: [PATCH v1 1/1] IB/hfi1: Don't cast parameter in bit operations

From: 'Andy Shevchenko'
Date: Wed Feb 23 2022 - 20:57:23 EST


On Wed, Feb 23, 2022 at 10:50:19PM +0000, David Laight wrote:
> From: 'Andy Shevchenko'
> > Sent: 23 February 2022 22:30
> > On Wed, Feb 23, 2022 at 09:44:32PM +0000, David Laight wrote:
> > > From: Andy Shevchenko
> > > > Sent: 23 February 2022 18:54

...

> > Either way it wastes cycles, the outcome depends on the actual distribution of
> > the interrupts across the bitmap. If it gathered closer to the beginning of the
> > bitmap, my code wins, otherwise the original ones.
>
> The loop in bitmap_empty() will kill you - even if the first word in non-zero.

What loop? Did you really look into implementation of bitmap_empty()?

--
With Best Regards,
Andy Shevchenko