Re: [PATCH] mlx5: avoid 64-bit division

From: Ariel Levkovich
Date: Tue May 28 2019 - 10:47:35 EST



On Mon, May 20, 2019 at 02:28:35PM +0300, Leon Romanovsky wrote:
> > On Mon, May 20, 2019 at 01:19:02PM +0200, Michal Kubecek wrote:
> > > Commit 25c13324d03d ("IB/mlx5: Add steering SW ICM device memory type")
> > > breaks i386 build by introducing three 64-bit divisions. As the divisor
> > > is MLX5_SW_ICM_BLOCK_SIZE() which is always a power of 2, we can replace
> > > the division with bit operations.
> >
> > Interesting, we tried to solve it differently.
> > I added it to our regression to be on the same side.

> This patch works for us.

Yes, this value is guaranteed to be a power of 2. We safely use round_up() instead as suggested in the patch.