From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 16/25] device-dax: use the dev_pagemap internal refcount Date: Fri, 28 Jun 2019 21:02:07 +0200 Message-ID: <20190628190207.GA9317@lst.de> References: <20190626122724.13313-17-hch@lst.de> <20190628153827.GA5373@mellanox.com> <20190628170219.GA3608@mellanox.com> <20190628182922.GA15242@mellanox.com> <20190628185152.GA9117@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Dan Williams Cc: Christoph Hellwig , Jason Gunthorpe , =?iso-8859-1?B?Suly9G1l?= Glisse , Ben Skeggs , "linux-mm@kvack.org" , "nouveau@lists.freedesktop.org" , "dri-devel@lists.freedesktop.org" , "linux-nvdimm@lists.01.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Andrew Morton List-Id: dri-devel@lists.freedesktop.org On Fri, Jun 28, 2019 at 11:59:19AM -0700, Dan Williams wrote: > It's a bug that the call to put_devmap_managed_page() was gated by > MEMORY_DEVICE_PUBLIC in release_pages(). That path is also applicable > to MEMORY_DEVICE_FSDAX because it needs to trigger the ->page_free() > callback to wake up wait_on_var() via fsdax_pagefree(). > > So I guess you could argue that the MEMORY_DEVICE_PUBLIC removal patch > left the original bug in place. In that sense we're no worse off, but > since we know about the bug, the fix and the patches have not been > applied yet, why not fix it now? The fix it now would simply be to apply Ira original patch now, but given that we are at -rc6 is this really a good time? And if we don't apply it now based on the quilt based -mm worflow it just seems a lot easier to apply it after my series. Unless we want to include it in the series, in which case I can do a quick rebase, we'd just need to make sure Andrew pulls it from -mm.