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From: Linus Walleij <linus.walleij@linaro.org>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Bob Pearson <rpearsonhpe@gmail.com>,
	Leon Romanovsky <leonro@nvidia.com>,
	Bernard Metzler <BMT@zurich.ibm.com>,
	linux-rdma@vger.kernel.org
Subject: Re: [PATCH] RDMA/rxe: Pass a pointer to virt_to_page()
Date: Thu, 30 Mar 2023 17:19:01 +0200	[thread overview]
Message-ID: <CACRpkdYyRjLyCjftqu3HwP4zBWpoGQgcBnxhosV_YFen-39Nwg@mail.gmail.com> (raw)
In-Reply-To: <ZCV7PwYwLVXGS202@nvidia.com>

On Thu, Mar 30, 2023 at 2:06 PM Jason Gunthorpe <jgg@nvidia.com> wrote:
> On Wed, Mar 29, 2023 at 09:45:45PM -0500, Bob Pearson wrote:
> > On 3/29/23 18:16, Jason Gunthorpe wrote:
> > > On Wed, Mar 29, 2023 at 04:28:08PM +0200, Linus Walleij wrote:
> > >
> > >> I'm a bit puzzled: could the above code (which exist in
> > >> three instances in the driver) even work as it is? Or is it not used?
> > >> Or is there some failover from DMA to something else that is constantly
> > >> happening?
> > >
> > > The physical address dma type IB_MR_TYPE_DMA is rarely used and maybe
> > > nobody ever tested it, at least in a configuration where kva != pa
> > >
> > > Then again, maybe I got it wrong and it is still a kva in this case
> > > because it is still ultimately DMA mapped when using IB_MR_TYPE_DMA?
> > >
> > > Bob?
> > >
> > > Jason
> >
> > In the amd64 environment I use to dev and test there is no difference AFAIK.
> > I have to go on faith that other platforms work but have very little experience.
>
> Honestly, I would be much happier if the virtual wrappers used
> physical not kva :\ But that is too much to ask
>
> So I suspsect I got it wrong and it is a kva still

OK I'll respin the first version of the patch but with the quirks making it work
on parisc.

Yours,
Linus Walleij

      reply	other threads:[~2023-03-30 15:20 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-24 10:32 [PATCH] RDMA/rxe: Pass a pointer to virt_to_page() Linus Walleij
2023-03-24 12:27 ` kernel test robot
2023-03-24 13:59 ` Jason Gunthorpe
2023-03-29 14:28   ` Linus Walleij
2023-03-29 20:17     ` Bob Pearson
2023-03-29 23:16     ` Jason Gunthorpe
2023-03-30  2:45       ` Bob Pearson
2023-03-30 12:06         ` Jason Gunthorpe
2023-03-30 15:19           ` Linus Walleij [this message]

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