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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 66CC1C4363D for ; Fri, 2 Oct 2020 05:59:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9BE20206E3 for ; Fri, 2 Oct 2020 05:59:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BE20206E3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B277A6B0062; Fri, 2 Oct 2020 01:59:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AAF426B0068; Fri, 2 Oct 2020 01:59:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 975D16B006C; Fri, 2 Oct 2020 01:59:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0089.hostedemail.com [216.40.44.89]) by kanga.kvack.org (Postfix) with ESMTP id 66F176B0062 for ; Fri, 2 Oct 2020 01:59:34 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 030A18249980 for ; Fri, 2 Oct 2020 05:59:34 +0000 (UTC) X-FDA: 77325933468.04.flock99_4909aa8271a1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id DC6988008B18 for ; Fri, 2 Oct 2020 05:59:33 +0000 (UTC) X-HE-Tag: flock99_4909aa8271a1 X-Filterd-Recvd-Size: 2067 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Fri, 2 Oct 2020 05:59:33 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id C3CBB68BEB; Fri, 2 Oct 2020 07:59:30 +0200 (CEST) Date: Fri, 2 Oct 2020 07:59:30 +0200 From: Christoph Hellwig To: Ralph Campbell Cc: linux-mm@kvack.org, kvm-ppc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dan Williams , Ira Weiny , Matthew Wilcox , Jerome Glisse , John Hubbard , Alistair Popple , Christoph Hellwig , Jason Gunthorpe , Bharata B Rao , Zi Yan , "Kirill A . Shutemov" , Yang Shi , Paul Mackerras , Ben Skeggs , Andrew Morton Subject: Re: [RFC PATCH v3 2/2] mm: remove extra ZONE_DEVICE struct page refcount Message-ID: <20201002055930.GB8891@lst.de> References: <20201001181715.17416-1-rcampbell@nvidia.com> <20201001181715.17416-3-rcampbell@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201001181715.17416-3-rcampbell@nvidia.com> User-Agent: Mutt/1.5.17 (2007-11-01) 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, Oct 01, 2020 at 11:17:15AM -0700, Ralph Campbell wrote: > ZONE_DEVICE struct pages have an extra reference count that complicates the > code for put_page() and several places in the kernel that need to check the > reference count to see that a page is not being used (gup, compaction, > migration, etc.). Clean up the code so the reference count doesn't need to > be treated specially for ZONE_DEVICE. > > Signed-off-by: Ralph Campbell Looks good, Reviewed-by: Christoph Hellwig