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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 22D8DC4338F for ; Sun, 15 Aug 2021 15:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F167B6120D for ; Sun, 15 Aug 2021 15:37:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238233AbhHOPht (ORCPT ); Sun, 15 Aug 2021 11:37:49 -0400 Received: from verein.lst.de ([213.95.11.211]:51934 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229603AbhHOPhr (ORCPT ); Sun, 15 Aug 2021 11:37:47 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 3DD6167357; Sun, 15 Aug 2021 17:37:14 +0200 (CEST) Date: Sun, 15 Aug 2021 17:37:13 +0200 From: Christoph Hellwig 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, John Hubbard Subject: Re: [PATCH v6 02/13] mm: remove extra ZONE_DEVICE struct page refcount Message-ID: <20210815153713.GA32384@lst.de> References: <20210813063150.2938-1-alex.sierra@amd.com> <20210813063150.2938-3-alex.sierra@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210813063150.2938-3-alex.sierra@amd.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 8ae31622deef..d48a1f0889d1 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1218,7 +1218,7 @@ __maybe_unused struct page *try_grab_compound_head(struct page *page, int refs, > static inline __must_check bool try_get_page(struct page *page) > { > page = compound_head(page); > - if (WARN_ON_ONCE(page_ref_count(page) <= 0)) > + if (WARN_ON_ONCE(page_ref_count(page) < (int)!is_zone_device_page(page))) Please avoid the overly long line. In fact I'd be tempted to just not bother here and keep the old, more lose check. Especially given that John has a patch ready that removes try_get_page entirely.