Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 14 Aug 2019 21:13:19 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Ralph Campbell <rcampbell@nvidia.com>
Cc:     linux-mm@kvack.org, Andrea Arcangeli <aarcange@redhat.com>,
        Christoph Hellwig <hch@lst.de>,
        John Hubbard <jhubbard@nvidia.com>,
        =?utf-8?B?SsOpcsO0bWU=?= Glisse <jglisse@redhat.com>,
        "Kuehling, Felix" <Felix.Kuehling@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>,
        "David (ChunMing) Zhou" <David1.Zhou@amd.com>,
        Dimitri Sivanich <sivanich@sgi.com>,
        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 <shangw@linux.vnet.ibm.com>,
        Andrea Righi <andrea@betterlinux.com>,
        Christoph Hellwig <hch@infradead.org>
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)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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 <jgg@mellanox.com>
> > 
> > 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