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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6C9F9C433DF for ; Thu, 25 Jun 2020 09:05:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0C61B20720 for ; Thu, 25 Jun 2020 09:05:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C61B20720 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4901B6B0002; Thu, 25 Jun 2020 05:05:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4404B6B0003; 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Thu, 25 Jun 2020 09:05:17 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E916CC0A; Thu, 25 Jun 2020 02:05:16 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5BB5F3F6CF; Thu, 25 Jun 2020 02:05:15 -0700 (PDT) Subject: Re: [PATCH v5 21/25] mm: Add arch hooks for saving/restoring tags To: Andrew Morton , Catalin Marinas Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, Will Deacon , Dave P Martin , Vincenzo Frascino , Szabolcs Nagy , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne References: <20200624175244.25837-1-catalin.marinas@arm.com> <20200624175244.25837-22-catalin.marinas@arm.com> <20200624114534.9520ba5ed235bc32bf1af3a2@linux-foundation.org> From: Steven Price Message-ID: <40250ed8-50fe-3945-d7d3-331e03b2abe8@arm.com> Date: Thu, 25 Jun 2020 10:04:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200624114534.9520ba5ed235bc32bf1af3a2@linux-foundation.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4D8DD1804B655 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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 24/06/2020 19:45, Andrew Morton wrote: > On Wed, 24 Jun 2020 18:52:40 +0100 Catalin Marinas wrote: > >> From: Steven Price >> >> Arm's Memory Tagging Extension (MTE) adds some metadata (tags) to >> every physical page, when swapping pages out to disk it is necessary to >> save these tags, and later restore them when reading the pages back. >> >> Add some hooks along with dummy implementations to enable the >> arch code to handle this. >> >> Three new hooks are added to the swap code: >> * arch_prepare_to_swap() and >> * arch_swap_invalidate_page() / arch_swap_invalidate_area(). >> One new hook is added to shmem: >> * arch_swap_restore_tags() >> >> ... >> >> --- a/include/linux/pgtable.h >> +++ b/include/linux/pgtable.h >> @@ -631,6 +631,29 @@ static inline int arch_unmap_one(struct mm_struct *mm, >> } >> #endif >> >> +#ifndef __HAVE_ARCH_PREPARE_TO_SWAP >> +static inline int arch_prepare_to_swap(struct page *page) >> +{ >> + return 0; >> +} >> +#endif >> + >> +#ifndef __HAVE_ARCH_SWAP_INVALIDATE >> +static inline void arch_swap_invalidate_page(int type, pgoff_t offset) >> +{ >> +} >> + >> +static inline void arch_swap_invalidate_area(int type) >> +{ >> +} >> +#endif >> + >> +#ifndef __HAVE_ARCH_SWAP_RESTORE_TAGS >> +static inline void arch_swap_restore_tags(swp_entry_t entry, struct page *page) >> +{ >> +} >> +#endif > > Presumably these three __HAVE_ARCH_ macros are to be defined in asm/pgtable.h? That would be the idea (see patch 22). However: Catalin - you've renamed __HAVE_ARCH_SWAP_RESTORE_TAGS in patch 22, but not here! Steve