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[156.34.48.30]) by smtp.gmail.com with ESMTPSA id c76sm8677260qkb.20.2020.11.02.09.16.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Nov 2020 09:16:40 -0800 (PST) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kZdRf-00FI9F-Az; Mon, 02 Nov 2020 13:16:39 -0400 Date: Mon, 2 Nov 2020 13:16:39 -0400 From: Jason Gunthorpe To: Daniel Vetter Cc: Christoph Hellwig , DRI Development , LKML , KVM list , Linux MM , Linux ARM , linux-samsung-soc , "open list:DMA BUFFER SHARING FRAMEWORK" , Daniel Vetter , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , J??r??me Glisse , Jan Kara Subject: Re: [PATCH v5 08/15] mm: Add unsafe_follow_pfn Message-ID: <20201102171639.GH36674@ziepe.ca> References: <20201030100815.2269-1-daniel.vetter@ffwll.ch> <20201030100815.2269-9-daniel.vetter@ffwll.ch> <20201102072931.GA16419@infradead.org> <20201102130115.GC36674@ziepe.ca> <20201102155256.GG36674@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Mon, Nov 02, 2020 at 05:42:20PM +0100, Daniel Vetter wrote: > > Need to hold the lock to check that and there are two ways to register > > notifiers these days, so it feels to expensive to me. > > Uh I mixed stuff up all along, struct mmu_notifier *subcription that > all the mmu notifier users use has the ->mm pointer we want right > there. That's good enough I think. Yah, if you can pass in one of those instead of the raw mm it would be fine Jason