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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 9831EC48BE5 for ; Thu, 17 Jun 2021 23:52:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FAA56128B for ; Thu, 17 Jun 2021 23:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232126AbhFQXyj (ORCPT ); Thu, 17 Jun 2021 19:54:39 -0400 Received: from mail110.syd.optusnet.com.au ([211.29.132.97]:57621 "EHLO mail110.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230484AbhFQXyi (ORCPT ); Thu, 17 Jun 2021 19:54:38 -0400 Received: from dread.disaster.area (pa49-179-138-183.pa.nsw.optusnet.com.au [49.179.138.183]) by mail110.syd.optusnet.com.au (Postfix) with ESMTPS id 2980A105DBE; Fri, 18 Jun 2021 09:52:27 +1000 (AEST) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1lu1oA-00DzCu-Kc; Fri, 18 Jun 2021 09:52:26 +1000 Date: Fri, 18 Jun 2021 09:52:26 +1000 From: Dave Chinner To: Alex Sierra Cc: akpm@linux-foundation.org, Felix.Kuehling@amd.com, linux-mm@kvack.org, rcampbell@nvidia.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, hch@lst.de, jgg@nvidia.com, jglisse@redhat.com Subject: Re: [PATCH v3 1/8] ext4/xfs: add page refcount helper Message-ID: <20210617235226.GI664593@dread.disaster.area> References: <20210617151705.15367-1-alex.sierra@amd.com> <20210617151705.15367-2-alex.sierra@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210617151705.15367-2-alex.sierra@amd.com> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=YKPhNiOx c=1 sm=1 tr=0 a=MnllW2CieawZLw/OcHE/Ng==:117 a=MnllW2CieawZLw/OcHE/Ng==:17 a=kj9zAlcOel0A:10 a=r6YtysWOX24A:10 a=Ikd4Dj_1AAAA:8 a=zd2uoN0lAAAA:8 a=7-415B0cAAAA:8 a=_NB1ZJQsyc3AttudJlgA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Thu, Jun 17, 2021 at 10:16:58AM -0500, Alex Sierra wrote: > From: Ralph Campbell > > There are several places where ZONE_DEVICE struct pages assume a reference > count == 1 means the page is idle and free. Instead of open coding this, > add a helper function to hide this detail. > > v2: > [AS]: rename dax_layout_is_idle_page func to dax_page_unused Did you even compile test this? > Signed-off-by: Ralph Campbell > Signed-off-by: Alex Sierra > --- > fs/dax.c | 4 ++-- > fs/ext4/inode.c | 5 +---- > fs/xfs/xfs_file.c | 4 +--- > include/linux/dax.h | 10 ++++++++++ > 4 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index 26d5dcd2d69e..321f4ddc6643 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, > for_each_mapped_pfn(entry, pfn) { > struct page *page = pfn_to_page(pfn); > > - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); > + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page)); Because you still use dax_layout_is_idle_page() here, not dax_page_unused()... > WARN_ON_ONCE(page->mapping && page->mapping != mapping); > page->mapping = NULL; > page->index = 0; > @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) > for_each_mapped_pfn(entry, pfn) { > struct page *page = pfn_to_page(pfn); > > - if (page_ref_count(page) > 1) > + if (!dax_layout_is_idle_page(page)) Here too. Cheers, Dave. -- Dave Chinner david@fromorbit.com