From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 1/6] mmput: use notifier chain to call subsystem exit handler. Date: Mon, 30 Jun 2014 17:40:42 +0200 Message-ID: <20140630154042.GD26537@8bytes.org> References: <1403920822-14488-1-git-send-email-j.glisse@gmail.com> <1403920822-14488-2-git-send-email-j.glisse@gmail.com> <019CCE693E457142B37B791721487FD91806B836@storexdag01.amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <019CCE693E457142B37B791721487FD91806B836-0nO7ALo/ziwxlywnonMhLEEOCMrvLtNR@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "Gabbay, Oded" Cc: Sherry Cheung , "linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org" , "hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org" , =?iso-8859-1?B?Suly9G1l?= Glisse , "aarcange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , Jatin Kumar , Lucien Dunning , "mgorman-l3A5Bk7waGM@public.gmane.org" , "jweiner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , Subhash Gutti , "riel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , John Hubbard , Mark Hairgrove , Cameron Buschardt , "peterz-hDdKplPs4pWWVfeAwA7xHQ@public.gmane.org" , Duncan Poole , "Cornwall, Jay" , "Lewycky, Andrew" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , Arvind Gopalakrishnan List-Id: linux-mm.kvack.org On Mon, Jun 30, 2014 at 02:41:24PM +0000, Gabbay, Oded wrote: > I did face some problems regarding the amd IOMMU v2 driver, which > changed its behavior (see commit "iommu/amd: Implement > mmu_notifier_release call-back") to use mmu_notifier_release and did > some "bad things" inside that > notifier (primarily, but not only, deleting the object which held the > mmu_notifier object itself, which you mustn't do because of the > locking). > > I'm thinking of changing that driver's behavior to use this new > mechanism instead of using mmu_notifier_release. Does that seem > acceptable ? Another solution will be to add a new mmu_notifier call, > but we already ruled that out ;) The mmu_notifier_release() function is exactly what this new notifier aims to do. Unless there is a very compelling reason to duplicate this functionality I stronly NACK this approach. Joerg