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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 68B7CC04EB9 for ; Wed, 5 Dec 2018 12:29:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 314112084C for ; Wed, 5 Dec 2018 12:29:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 314112084C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727840AbeLEM3P (ORCPT ); Wed, 5 Dec 2018 07:29:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40842 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727809AbeLEM3N (ORCPT ); Wed, 5 Dec 2018 07:29:13 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6A6FB307D975; Wed, 5 Dec 2018 12:29:11 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-65.ams2.redhat.com [10.36.117.65]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6BC0A82719; Wed, 5 Dec 2018 12:28:52 +0000 (UTC) From: David Hildenbrand To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-mediatek@lists.infradead.org, David Hildenbrand , Albert Ou , Alexander Duyck , Andrew Morton , Anthony Yznaga , Arnd Bergmann , Benjamin Herrenschmidt , Bhupesh Sharma , Catalin Marinas , Christophe Leroy , Dan Williams , Dave Kleikamp , David Airlie , Geert Uytterhoeven , Greg Kroah-Hartman , Heiko Carstens , James Morse , Kees Cook , Marc Zyngier , Mark Rutland , Martin Schwidefsky , Matthew Wilcox , Michael Ellerman , Michal Hocko , Michal Hocko , Mike Rapoport , Miles Chen , Palmer Dabbelt , Paul Mackerras , Pavel Tatashin , Souptick Joarder , Stephen Rothwell , Tobias Klauser , Vasily Gorbik , Will Deacon Subject: [PATCH RFC 0/7] mm: PG_reserved cleanups and documentation Date: Wed, 5 Dec 2018 13:28:44 +0100 Message-Id: <20181205122851.5891-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Wed, 05 Dec 2018 12:29:13 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I was recently going over all users of PG_reserved. Short story: it is difficult and sometimes not really clear if setting/checking for PG_reserved is only a relict from the past. Easy to break things. I had way more cleanups in this series inititally, but some architectures take PG_reserved as a way to apply a different caching strategy (for MMIO pages). So I decided to only include the most obvious changes (that are less likely to break something). So let's see if the documentation update for PG_reserved I crafted actually covers most cases or if there is plenty more. Most notably, for device memory we can hopefully soon stop setting it PG_reserved I only briefly tested this on s390x. David Hildenbrand (7): agp: efficeon: no need to set PG_reserved on GATT tables s390/vdso: don't clear PG_reserved powerpc/vdso: don't clear PG_reserved riscv/vdso: don't clear PG_reserved m68k/mm: use __ClearPageReserved() arm64: kexec: no need to ClearPageReserved() mm: better document PG_reserved arch/arm64/kernel/machine_kexec.c | 1 - arch/m68k/mm/memory.c | 2 +- arch/powerpc/kernel/vdso.c | 2 -- arch/riscv/kernel/vdso.c | 1 - arch/s390/kernel/vdso.c | 2 -- drivers/char/agp/efficeon-agp.c | 2 -- include/linux/page-flags.h | 18 ++++++++++++++++-- 7 files changed, 17 insertions(+), 11 deletions(-) -- 2.17.2