Re: [PATCH v4 0/1] Use HMM for ODP v4

From: Jerome Glisse
Date: Thu May 23 2019 - 11:07:35 EST


On Wed, May 22, 2019 at 08:57:37PM -0300, Jason Gunthorpe wrote:
> On Wed, May 22, 2019 at 01:48:52PM -0400, Jerome Glisse wrote:
>
> > > > So attached is a rebase on top of 5.2-rc1, i have tested with pingpong
> > > > (prefetch and not and different sizes). Seems to work ok.
> > >
> > > Urk, it already doesn't apply to the rdma tree :(
> > >
> > > The conflicts are a little more extensive than I'd prefer to handle..
> > > Can I ask you to rebase it on top of this branch please:
> > >
> > > https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=wip/jgg-for-next
> > >
> > > Specifically it conflicts with this patch:
> > >
> > > https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/commit/?h=wip/jgg-for-next&id=d2183c6f1958e6b6dfdde279f4cee04280710e34
>
> There is at least one more serious blocker here:
>
> config ARCH_HAS_HMM_MIRROR
> bool
> default y
> depends on (X86_64 || PPC64)
> depends on MMU && 64BIT
>
> I can't loose ARM64 support for ODP by merging this, that is too
> serious of a regression.
>
> Can you fix it?

5.2 already has patch to fix the Kconfig (ARCH_HAS_HMM_MIRROR and
ARCH_HAS_HMM_DEVICE replacing ARCH_HAS_HMM) I need to update nouveau
in 5.3 so that i can drop the old ARCH_HAS_HMM and then convert
core mm in 5.4 to use ARCH_HAS_HMM_MIRROR and ARCH_HAS_HMM_DEVICE
instead of ARCH_HAS_HMM

Adding ARM64 to ARCH_HAS_HMM_MIRROR should not be an issue i would
need access to an ARM64 to test as i did not wanted to enable it
without testing.

So it seems it will have to wait 5.4 for ODP. I will re-spin the
patch for ODP once i am done reviewing Ralph changes and yours
for 5.3.

Cheers,
Jérôme