Re: [PATCH] staging: gasket: Convert get_user_pages*() --> pin_user_pages*()

From: Dan Carpenter
Date: Fri May 29 2020 - 03:45:34 EST


On Fri, May 29, 2020 at 12:38:20AM -0700, John Hubbard wrote:
> On 2020-05-28 23:27, Souptick Joarder wrote:
> > On Fri, May 29, 2020 at 11:46 AM Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
> > >
> > > On Thu, May 28, 2020 at 4:34 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> > > >
> > > > On Thu, May 28, 2020 at 02:32:42AM +0530, Souptick Joarder wrote:
> > > > > This code was using get_user_pages_fast(), in a "Case 2" scenario
> > > > > (DMA/RDMA), using the categorization from [1]. That means that it's
> > > > > time to convert the get_user_pages_fast() + put_page() calls to
> > > > > pin_user_pages_fast() + unpin_user_page() calls.
> > > >
> > > > You are saying that the page is used for DIO and not DMA, but it sure
> > > > looks to me like it is used for DMA.
> > >
> > > No, I was referring to "Case 2" scenario in change log which means it is
> > > used for DMA, not DIO.
>
> Hi,
>
> Dan, I also uncertain as to how you read this as referring to DIO. Case 2 is
> DMA or RDMA, and in fact the proposed commit log says both of those things:
> Case 2 and DMA/RDMA. I don't see "DIO" anywhere here...

I thought he meant that the original code was appropriate for DMA and he
was fixing it. :P

regards,
dan carpenter