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=ham 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 841AFC2B9F4 for ; Thu, 17 Jun 2021 23:52:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1F2C06128B for ; Thu, 17 Jun 2021 23:52:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F2C06128B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 68FAB6B0070; Thu, 17 Jun 2021 19:52:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 63F7D6B0071; Thu, 17 Jun 2021 19:52:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 491DA6B0072; Thu, 17 Jun 2021 19:52:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0240.hostedemail.com [216.40.44.240]) by kanga.kvack.org (Postfix) with ESMTP id 160346B0070 for ; Thu, 17 Jun 2021 19:52:32 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B16F5BBFE for ; Thu, 17 Jun 2021 23:52:31 +0000 (UTC) X-FDA: 78264867702.09.9C593DB Received: from mail110.syd.optusnet.com.au (mail110.syd.optusnet.com.au [211.29.132.97]) by imf24.hostedemail.com (Postfix) with ESMTP id 0800BA000270 for ; Thu, 17 Jun 2021 23:52:30 +0000 (UTC) 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 Authentication-Results: imf24.hostedemail.com; dkim=none; spf=none (imf24.hostedemail.com: domain of david@fromorbit.com has no SPF policy when checking 211.29.132.97) smtp.mailfrom=david@fromorbit.com; dmarc=none X-Stat-Signature: kh3gt9aj33yy36eujaqffw5wdryasof9 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0800BA000270 X-HE-Tag: 1623973950-924916 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 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