From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerome Glisse Subject: Re: [PATCH v4 0/1] Use HMM for ODP v4 Date: Thu, 23 May 2019 13:33:03 -0400 Message-ID: <20190523173302.GD5104@redhat.com> References: <20190411181314.19465-1-jglisse@redhat.com> <20190506195657.GA30261@ziepe.ca> <20190521205321.GC3331@redhat.com> <20190522005225.GA30819@ziepe.ca> <20190522174852.GA23038@redhat.com> <20190522235737.GD15389@ziepe.ca> <20190523150432.GA5104@redhat.com> <20190523154149.GB12159@ziepe.ca> <20190523155207.GC5104@redhat.com> <20190523163429.GC12159@ziepe.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20190523163429.GC12159@ziepe.ca> Sender: linux-kernel-owner@vger.kernel.org To: Jason Gunthorpe Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, Leon Romanovsky , Doug Ledford , Artemy Kovalyov , Moni Shoua , Mike Marciniszyn , Kaike Wan , Dennis Dalessandro List-Id: linux-rdma@vger.kernel.org On Thu, May 23, 2019 at 01:34:29PM -0300, Jason Gunthorpe wrote: > On Thu, May 23, 2019 at 11:52:08AM -0400, Jerome Glisse wrote: > > On Thu, May 23, 2019 at 12:41:49PM -0300, Jason Gunthorpe wrote: > > > On Thu, May 23, 2019 at 11:04:32AM -0400, Jerome Glisse wrote: > > > > 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 > > > > > > Newer than 5.2-rc1? Is this why ARCH_HAS_HMM_MIRROR is not used anywhere? > > > > Yes this is multi-step update, first add the new Kconfig release n, > > update driver in release n+1, update core Kconfig in release n+2 > > > > So we are in release n (5.2), in 5.3 i will update nouveau and amdgpu > > so that in 5.4 in ca remove the old ARCH_HAS_HMM > > Why don't you just send the patch for both parts to mm or to DRM? > > This is very normal - as long as the resulting conflicts would be > small during there is no reason not to do this. Can you share the > combined patch? This was tested in the past an resulted in failure. So for now i am taking the simplest and easiest path with the least burden for every maintainer. It only complexify my life. Note that mm is not a git tree and thus i can not play any git trick to help in this endeavor. > > > If mm takes the fixup patches so hmm mirror is as reliable as ODP's > > > existing stuff, and patch from you to enable ARM64, then we can > > > continue to merge into 5.3 > > > > > > So, let us try to get acks on those other threads.. > > > > I will be merging your patchset and Ralph and repost, they are only > > minor change mostly that you can not update the driver API in just > > one release. > > Of course you can, we do it all the time. It requires some > co-ordination, but as long as the merge conflicts are not big it is > fine. > > Merge the driver API change and the call site updates to -mm and > refain from merging horrendously conflicting patches through DRM. > > In the case of the changes in my HMM RFC it is something like 2 > lines in DRM that need touching, no problem at all. > > If you want help I can volunteer make a hmm PR for Linus just for this > during the merge window - but Andrew would need to agree and ack the > patches. This was tested in the past and i do not want to go over this issue again (or re-iterate the long emails discussion associated with that). It failed and it put the burden on every maintainers. So it is easier to do the multi-step thing. You can take a peak at Ralph patchset and yours into one with minor changes here: https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-5.3 I am about to start testing it with nouveau, amdgpu and RDMA. Cheers, Jérôme