RE: [PATCH 05/12] net: mana: Set the DMA device max page size

Long Li
2022-05-17T19:33:01Z

> Subject: Re: [PATCH 05/12] net: mana: Set the DMA device max page size
>
> On Tue, May 17, 2022 at 02:04:29AM -0700, longli@linuxonhyperv.com wrote:
> > From: Long Li <longli@microsoft.com>
> >
> > The system chooses default 64K page size if the device does not
> > specify the max page size the device can handle for DMA. This do not
> > work well when device is registering large chunk of memory in that a
> > large page size is more efficient.
> >
> > Set it to the maximum hardware supported page size.
>
> For RDMA devices this should be set to the largest segment size an ib_sge can
> take in when posting work. It should not be the page size of MR. 2M is a weird
> number for that, are you sure it is right?

Yes, this is the maximum page size used in hardware page tables.

Long

>
> Jason