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[156.34.55.100]) by smtp.gmail.com with ESMTPSA id i5sm756517qti.0.2019.08.14.17.13.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 14 Aug 2019 17:13:20 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1hy3OJ-0003bl-SN; Wed, 14 Aug 2019 21:13:19 -0300 Date: Wed, 14 Aug 2019 21:13:19 -0300 From: Jason Gunthorpe To: Ralph Campbell Cc: linux-mm@kvack.org, Andrea Arcangeli , Christoph Hellwig , John Hubbard , =?utf-8?B?SsOpcsO0bWU=?= Glisse , "Kuehling, Felix" , Alex Deucher , Christian =?utf-8?B?S8O2bmln?= , "David (ChunMing) Zhou" , Dimitri Sivanich , dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux-foundation.org, intel-gfx@lists.freedesktop.org, Gavin Shan , Andrea Righi , Christoph Hellwig Subject: Re: [PATCH v3 hmm 03/11] mm/mmu_notifiers: add a get/put scheme for the registration Message-ID: <20190815001319.GF11200@ziepe.ca> References: <20190806231548.25242-1-jgg@ziepe.ca> <20190806231548.25242-4-jgg@ziepe.ca> <0a23adb8-b827-cd90-503e-bfa84166c67e@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0a23adb8-b827-cd90-503e-bfa84166c67e@nvidia.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Aug 14, 2019 at 02:20:31PM -0700, Ralph Campbell wrote: > > On 8/6/19 4:15 PM, Jason Gunthorpe wrote: > > From: Jason Gunthorpe > > > > Many places in the kernel have a flow where userspace will create some > > object and that object will need to connect to the subsystem's > > mmu_notifier subscription for the duration of its lifetime. > > > > In this case the subsystem is usually tracking multiple mm_structs and it > > is difficult to keep track of what struct mmu_notifier's have been > > allocated for what mm's. > > > > Since this has been open coded in a variety of exciting ways, provide core > > functionality to do this safely. > > > > This approach uses the strct mmu_notifier_ops * as a key to determine if > > s/strct/struct Yes, thanks for all of this, I like having comments, but I'm a terrible proofreader :( Jason