On 26/04/17 01:44 AM, Christoph Hellwig wrote:
> I think we'll at least need a draft of those to make sense of these
> patches. Otherwise they just look very clumsy.
Ok, what follows is a draft patch attempting to show where I'm thinking
of going with this. Obviously it will not compile because
On 27/04/17 09:27 AM, Jason Gunthorpe wrote:
> On Thu, Apr 27, 2017 at 08:53:38AM +0200, Christoph Hellwig wrote:
> How about first switching as many call sites as possible to use
> sg_copy_X_buffer instead of kmap?
Yeah, I could look at doing that first.
One problem is we might get more Naks
On 27/04/17 12:53 AM, Christoph Hellwig wrote:
> I think you'll need to follow the existing kmap semantics and never
> fail the iomem version either. Otherwise you'll have a special case
> that's almost never used that has a different error path.
>
> Again, wrong way. Suddenly making things
On Thu, Apr 27, 2017 at 08:53:38AM +0200, Christoph Hellwig wrote:
> > The main difficulty we
> > have now is that neither of those functions are expected to fail and we
> > need them to be able to in cases where the page doesn't map to system
> > RAM. This patch series is trying to address it
On Wed, Apr 26, 2017 at 12:11:33PM -0600, Logan Gunthorpe wrote:
> Ok, well for starters I think you are mistaken about kmap being able to
> fail. I'm having a hard time finding many users of that function that
> bother to check for an error when calling it.
A quick audit of the arch code shows
On 26/04/17 02:59 AM, wrote:
> Good to know that somebody is working on this. Those problems troubled
> us as well.
Thanks Christian. It's a daunting problem and a there's a lot of work to
do before we will ever be where we need to be so any help, even an ack,
is greatly appreciated.
Logan
On 26/04/17 01:44 AM, Christoph Hellwig wrote:
> I think we'll at least need a draft of those to make sense of these
> patches. Otherwise they just look very clumsy.
Ok, I'll work up a draft proposal and send it in a couple days. But
without a lot of cleanup such as this series it's not going
Am 25.04.2017 um 20:20 schrieb Logan Gunthorpe:
This patch introduces functions which kmap the pages inside an sgl.
These functions replace a common pattern of kmap(sg_page(sg)) that is
used in more than 50 places within the kernel.
The motivation for this work is to eventually safely support
On Tue, Apr 25, 2017 at 12:20:48PM -0600, Logan Gunthorpe wrote:
> This patch introduces functions which kmap the pages inside an sgl.
> These functions replace a common pattern of kmap(sg_page(sg)) that is
> used in more than 50 places within the kernel.
>
> The motivation for this work is to
