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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 EDC52C433E0 for ; Wed, 24 Jun 2020 18:38:29 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C39C720724 for ; Wed, 24 Jun 2020 18:38:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BL87k1+y"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EWFa2tyg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C39C720724 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=E4Lu0ZfWCAs3cIC+2LhstViWPoswcbkCmjy4zKb+kkQ=; b=BL87k1+yNu7Ysiilxw/45QPSn /NnYS3/w/93Kskb96I5tLb1jDl9DS/GhjCXkavLBTiQhywqcc04xUM14IZRYY7rlXNYO75ANqtswu LagaivgrrhXvGn/VpcaYHsRDopLz4lnunAhqOyl6bgjVvJrbg6pxSk7uYHzLakhdlc+33ibBsZ+r7 cuAae3heHqTWr7Fa3fTYkkZ6S7tWH14bFiGmhl84euOF3RIBJ1q2YJU91bf0XbWy4EbvULwHnSGYQ fYNV/MfDGjVRBOu3Dpy0CPHObIUMyoQJ3hyndH+H9uhS/l5IfG/lUD7MUzuwvxLQffLdtA8/bjKMs /eRX6Veyg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1joAGQ-00076W-R6; Wed, 24 Jun 2020 18:36:50 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1joAGO-00075m-RM for linux-arm-kernel@merlin.infradead.org; Wed, 24 Jun 2020 18:36:48 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=xU36C/WiUNJodzhyk8EQn6FWj5wnkbbbz+a3PgaakRo=; b=EWFa2tygln6IJibkrOIR04l1VN DFpaShPToa/lioJyeicFoPHR9h74piP9grxP7t70i3icz3UrsRveU8bdxf7Eb7sNhwQFwYWPdHHPf JynY6wE7/8oHaqVr/x9eGQsckraSkQNiFWnzRN2c7tghXgLy5wEMN7AviqSRy8Az6Jwi0ErXDHqTi l+xYOh7qNTaZJ4MfPk8hhgRD77TwK6NBR9nMT3jeonoKd2h4xJUWF/pHChpP/+1pi1E02eAeYx8f+ dAUMAyenSOB/zm7SSV1NB8OqY1JibLu9cxnSRjSlorSh8bnR5ApktJsRaYh+MOTH1UY2TIB5CuBYc GT+d6T9Q==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1joAGN-0004fD-Ag; Wed, 24 Jun 2020 18:36:47 +0000 Date: Wed, 24 Jun 2020 19:36:47 +0100 From: Matthew Wilcox To: Andrew Morton Subject: Re: [PATCH v5 06/25] mm: Add PG_ARCH_2 page flag Message-ID: <20200624183647.GU21350@casper.infradead.org> References: <20200624175244.25837-1-catalin.marinas@arm.com> <20200624175244.25837-7-catalin.marinas@arm.com> <20200624113307.6165b3db2404c9d37b870a90@linux-foundation.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200624113307.6165b3db2404c9d37b870a90@linux-foundation.org> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Szabolcs Nagy , Catalin Marinas , Kevin Brodsky , Steven Price , Peter Collingbourne , linux-mm@kvack.org, Andrey Konovalov , Vincenzo Frascino , Will Deacon , Dave P Martin , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jun 24, 2020 at 11:33:07AM -0700, Andrew Morton wrote: > On Wed, 24 Jun 2020 18:52:25 +0100 Catalin Marinas wrote: > > > From: Steven Price > > > > For arm64 MTE support it is necessary to be able to mark pages that > > contain user space visible tags that will need to be saved/restored e.g. > > when swapped out. > > > > To support this add a new arch specific flag (PG_ARCH_2) that arch code > > can opt into using ARCH_USES_PG_ARCH_2. > > > > ... > > > > --- a/fs/proc/page.c > > +++ b/fs/proc/page.c > > @@ -217,6 +217,9 @@ u64 stable_page_flags(struct page *page) > > u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2); > > u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1); > > u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1); > > +#ifdef CONFIG_ARCH_USES_PG_ARCH_2 > > + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2); > > +#endif > > Do we need CONFIG_ARCH_USES_PG_ARCH_2? What would be the downside to > giving every architecture a PG_arch_2, but only arm64 uses it (at > present)? 32-bit architectures don't have space for it. We could condition it on CONFIG_64BIT instead. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel