Re: [PATCH 0/2] Two bug-fixes for HMM

From: "Kuehling, Felix" <Felix.Kuehling@amd.com>
To: Jason Gunthorpe <jgg@ziepe.ca>,
	"Deucher, Alexander" <Alexander.Deucher@amd.com>,
	"airlied@gmail.com" <airlied@gmail.com>
Cc: "jglisse@redhat.com" <jglisse@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"amd-gfx@lists.freedesktop.org" <amd-gfx@lists.freedesktop.org>
Subject: Re: [PATCH 0/2] Two bug-fixes for HMM
Date: Thu, 6 Jun 2019 19:16:48 +0000	[thread overview]
Message-ID: <c42a620d-ce5f-def3-32e3-1e5482a2540e@amd.com> (raw)
In-Reply-To: <20190606151149.GA5506@ziepe.ca>

[resent with correct address for Alex]

On 2019-06-06 11:11 a.m., Jason Gunthorpe wrote:

> On Fri, May 10, 2019 at 07:53:21PM +0000, Kuehling, Felix wrote:
>> These problems were found in AMD-internal testing as we're working on
>> adopting HMM. They are rebased against glisse/hmm-5.2-v3. We'd like 
>> to get
>> them applied to a mainline Linux kernel as well as drm-next and
>> amd-staging-drm-next sooner rather than later.
>>
>> Currently the HMM in amd-staging-drm-next is quite far behind hmm-5.2-v3,
>> but the driver changes for HMM are expected to land in 5.2 and will 
>> need to
>> be rebased on those HMM changes.
>>
>> I'd like to work out a flow between Jerome, Dave, Alex and myself that
>> allows us to test the latest version of HMM on amd-staging-drm-next so
>> that ideally everything comes together in master without much need for
>> rebasing and retesting.
> I think we have that now, I'm running a hmm.git that is clean and can
> be used for merging into DRM related trees (and RDMA). I've commited
> to send this tree to Linus at the start of the merge window.
>
> See here:
>
> https://lore.kernel.org/lkml/20190524124455.GB16845@ziepe.ca/
>
> The tree is here:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=hmm
>
> However please consult with me before making a merge commit to be
> co-ordinated. Thanks
>
> I see in this thread that AMDGPU missed 5.2 beacause of the
> co-ordination problems this tree is intended to solve, so I'm very
> hopeful this will help your work move into 5.3!

Thanks Jason. Our two patches below were already included in the MM tree 
(https://ozlabs.org/~akpm/mmots/broken-out/). With your new hmm.git, 
does that mean HMM fixes and changes will no longer go through Andrew 
Morton but directly through your tree to Linus?

We have also applied the two patches to our internal tree which is 
currently based on 5.2-rc1 so we can make progress.

Alex, I think merging hmm would be an extra step every time you rebase 
amd-staging-drm-next. We could probably also merge hmm at other times as 
needed. Do you think this would cause trouble or confusion for 
upstreaming through drm-next?

Regards,
   Felix

>
>> Maybe having Jerome's latest HMM changes in drm-next. However, that may
>> create dependencies where Jerome and Dave need to coordinate their pull-
>> requests for master.
>>
>> Felix Kuehling (1):
>> mm/hmm: Only set FAULT_FLAG_ALLOW_RETRY for non-blocking
>>
>> Philip Yang (1):
>> mm/hmm: support automatic NUMA balancing
> I've applied both of these patches with Jerome's Reviewed-by to
> hmm.git and added the missed Signed-off-by
>
> If you test and confirm I think this branch would be ready for merging
> toward the AMD tree.
> Regards,
> Jason