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=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 95546C4338F for ; Sun, 15 Aug 2021 15:37:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2450961208 for ; Sun, 15 Aug 2021 15:37:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2450961208 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C0E4D6B0072; Sun, 15 Aug 2021 11:37:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BBEA16B0073; Sun, 15 Aug 2021 11:37:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD5466B0074; Sun, 15 Aug 2021 11:37:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0068.hostedemail.com [216.40.44.68]) by kanga.kvack.org (Postfix) with ESMTP id 9092E6B0072 for ; Sun, 15 Aug 2021 11:37:18 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 44BC21CB34 for ; Sun, 15 Aug 2021 15:37:18 +0000 (UTC) X-FDA: 78477718956.02.FCAA38A Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf05.hostedemail.com (Postfix) with ESMTP id 7BF76502B162 for ; Sun, 15 Aug 2021 15:37:17 +0000 (UTC) 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) X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7BF76502B162 X-Stat-Signature: bntj9aao78mdgpyrfe33ax8fdymbowg3 Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=none; spf=none (imf05.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de X-HE-Tag: 1629041837-201822 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: > 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.