On Tue, May 17, 2022 at 02:04:29AM -0700, [email protected] wrote:
> From: Long Li <[email protected]>
>
> 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?
Jason
> Subject: Re: [PATCH 05/12] net: mana: Set the DMA device max page size
>
> On Tue, May 17, 2022 at 02:04:29AM -0700, [email protected] wrote:
> > From: Long Li <[email protected]>
> >
> > 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