From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id E1FBC21276BA6 for ; Fri, 28 Jun 2019 12:02:09 -0700 (PDT) Date: Fri, 28 Jun 2019 21:02:07 +0200 From: Christoph Hellwig Subject: Re: [PATCH 16/25] device-dax: use the dev_pagemap internal refcount 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-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dan Williams Cc: "linux-nvdimm@lists.01.org" , "nouveau@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linux-mm@kvack.org" , =?iso-8859-1?B?Suly9G1l?= Glisse , Jason Gunthorpe , Ben Skeggs , "linux-pci@vger.kernel.org" , Andrew Morton , Christoph Hellwig List-ID: 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. _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F29FC5B578 for ; Fri, 28 Jun 2019 19:02:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55E02206A2 for ; Fri, 28 Jun 2019 19:02:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727040AbfF1TCK (ORCPT ); Fri, 28 Jun 2019 15:02:10 -0400 Received: from verein.lst.de ([213.95.11.211]:40914 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726565AbfF1TCK (ORCPT ); Fri, 28 Jun 2019 15:02:10 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id D53A7227A81; Fri, 28 Jun 2019 21:02:07 +0200 (CEST) Date: Fri, 28 Jun 2019 21:02:07 +0200 From: Christoph Hellwig 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 Subject: Re: [PATCH 16/25] device-dax: use the dev_pagemap internal refcount 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 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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.