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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 A9C60C433DF for ; Mon, 15 Jun 2020 13:16:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 71F132074D for ; Mon, 15 Jun 2020 13:16:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 71F132074D 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 0B7776B000A; Mon, 15 Jun 2020 09:16:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0677D6B0010; Mon, 15 Jun 2020 09:16:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EBFE06B0022; Mon, 15 Jun 2020 09:16:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0145.hostedemail.com [216.40.44.145]) by kanga.kvack.org (Postfix) with ESMTP id D1E706B000A for ; Mon, 15 Jun 2020 09:16:53 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 68276181ABE85 for ; Mon, 15 Jun 2020 13:16:53 +0000 (UTC) X-FDA: 76931496306.15.metal81_2c0403026df6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id 48D561802F491 for ; Mon, 15 Jun 2020 13:15:40 +0000 (UTC) X-HE-Tag: metal81_2c0403026df6 X-Filterd-Recvd-Size: 3636 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Mon, 15 Jun 2020 13:15:39 +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 A6C2031B; Mon, 15 Jun 2020 06:15:38 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.79.186]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2D45C3F6CF; Mon, 15 Jun 2020 06:15:34 -0700 (PDT) From: Anshuman Khandual To: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, ziy@nvidia.com, Anshuman Khandual , Marc Zyngier , Suzuki Poulose , linux-kernel@vger.kernel.org Subject: [RFC V2 2/2] arm64/mm: Enable THP migration Date: Mon, 15 Jun 2020 18:45:18 +0530 Message-Id: <1592226918-26378-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1592226918-26378-1-git-send-email-anshuman.khandual@arm.com> References: <1592226918-26378-1-git-send-email-anshuman.khandual@arm.com> X-Rspamd-Queue-Id: 48D561802F491 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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: In certain page migration situations, a THP page can be migrated without being split into it's constituent subpages. This saves time required to split a THP and put it back together when required. But it also saves an wider address range translation covered by a single TLB entry, reducing future page fault costs. A previous patch changed platform THP helpers per generic memory semantics, clearing the path for THP migration support. This adds two more THP helpers required to create PMD migration swap entries. Now just enable HP migration via ARCH_ENABLE_THP_MIGRATION. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Marc Zyngier Cc: Suzuki Poulose Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- arch/arm64/Kconfig | 4 ++++ arch/arm64/include/asm/pgtable.h | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 31380da53689..01d432dc813e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1874,6 +1874,10 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION def_bool y depends on HUGETLB_PAGE && MIGRATION +config ARCH_ENABLE_THP_MIGRATION + def_bool y + depends on TRANSPARENT_HUGEPAGE + menu "Power management options" source "kernel/power/Kconfig" diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 560be593a8dc..892c30129cd2 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -907,6 +907,16 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +#define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) }) + +/* + * pmd_present() must return false for a swap PMD entry. + * Just explicitly clear PMD_TABLE_BIT while converting. + */ +#define __swp_entry_to_pmd(swp) __pmd((swp).val & ~PMD_TABLE_BIT) +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ + /* * Ensure that there are not more swap files than can be encoded in the kernel * PTEs. -- 2.20.1