From: Jason Gunthorpe Date: Mon, 20 Jul 2020 18:41:19 +0000 Subject: Re: [PATCH v2 0/5] mm/migrate: avoid device private invalidations Message-Id: <20200720184119.GT2021248@mellanox.com> List-Id: References: <20200713172149.2310-1-rcampbell@nvidia.com> In-Reply-To: <20200713172149.2310-1-rcampbell@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Ralph Campbell Cc: linux-rdma@vger.kernel.org, linux-mm@kvack.org, nouveau@lists.freedesktop.org, kvm-ppc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Jerome Glisse , John Hubbard , Christoph Hellwig , Andrew Morton , Shuah Khan , Ben Skeggs , Bharata B Rao On Mon, Jul 13, 2020 at 10:21:44AM -0700, Ralph Campbell wrote: > The goal for this series is to avoid device private memory TLB > invalidations when migrating a range of addresses from system > memory to device private memory and some of those pages have already > been migrated. The approach taken is to introduce a new mmu notifier > invalidation event type and use that in the device driver to skip > invalidation callbacks from migrate_vma_setup(). The device driver is > also then expected to handle device MMU invalidations as part of the > migrate_vma_setup(), migrate_vma_pages(), migrate_vma_finalize() process. > Note that this is opt-in. A device driver can simply invalidate its MMU > in the mmu notifier callback and not handle MMU invalidations in the > migration sequence. > > This series is based on Jason Gunthorpe's HMM tree (linux-5.8.0-rc4). > > Also, this replaces the need for the following two patches I sent: > ("mm: fix migrate_vma_setup() src_owner and normal pages") > https://lore.kernel.org/linux-mm/20200622222008.9971-1-rcampbell@nvidia.com > ("nouveau: fix mixed normal and device private page migration") > https://lore.kernel.org/lkml/20200622233854.10889-3-rcampbell@nvidia.com > > Changes in v2: > Rebase to Jason Gunthorpe's HMM tree. > Added reviewed-by from Bharata B Rao. > Rename the mmu_notifier_range::data field to migrate_pgmap_owner as > suggested by Jason Gunthorpe. I didn't see anything stand out in this at this point, did you intend this to go to the HMM tree? Thanks, Jason