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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2E7DCCA480 for ; Wed, 6 Jul 2022 22:01:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234547AbiGFWBE (ORCPT ); Wed, 6 Jul 2022 18:01:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234201AbiGFWA4 (ORCPT ); Wed, 6 Jul 2022 18:00:56 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24BDA1A3AB for ; Wed, 6 Jul 2022 15:00:54 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-31cdce3ed04so33177777b3.13 for ; Wed, 06 Jul 2022 15:00:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc:content-transfer-encoding; bh=Yske1o/9q5kvxCT6Do7fK+m0Z7RMKAIlwEA5dqQMV6o=; b=ScyLwm63xSUVYY78eVpIKf7E4l6uHPJ8SKqWyYLqNgfcQS9rJpZhYXa+GvIYC8VFxz 2VFStSncvwevlF5a8SeHX4Xsz1oxV5uuYYiB5ijS1hgFnqmnWUZ92SAkit2dsdOrKkVm doRskpr19skWYdTit7iDaFWDHSkEjmp1FnyOwnhb4K1iob0FZUGliEmOjr11tQKlaxMl A7gk8PUbqgtBAB5FxJW674j5ErsQXUNEF0mV9mDiI18iHiW2zTe0Jvp4coFt/YGkO03P +mGZgU80OTVBNdIcmd9CUSdknj31pHlFfc27NA1Hoqf7YpOu3eL0SW+Jp946t/R7w6FH wLdA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc:content-transfer-encoding; bh=Yske1o/9q5kvxCT6Do7fK+m0Z7RMKAIlwEA5dqQMV6o=; b=Wa9o3q5jcKHWZ2PemkB7DBj/4GtXBZtnogfSIJmIeCfuASmSlKxCPU5lizUaDuTCFw PkojdqgQVEhNHxx/uNWI1ZmmnBDdloiJFhDB/qWJi38IK7/kCKRwlqrLNq8fw632wY/G XjnG53JUXCI3WnrKuoIXvEnFILmmLxHgfjYtv7vUfkyf3Nq0rLDPabrffMAZXpxk3R2U mserCHnYZTSgQsfWCWEZ7ncXXr49vFONTV6FUglOgAGH6yPxenfFBi2sAuRN9uXGP5/M LjpmMvfe0XkfabJttJ1NVl6F/QoBvJyTRzzkMkPZmfx00JxVzc33wbrdFx5vZQ+q3uHK iTpA== X-Gm-Message-State: AJIora+1AbF+KftBLy3Q3McVbMFGvCp3TCBLocmf4ee9ZpgyZdb+1irp noswyJisBJTKQck86Wu6pGS5QxBXZKA= X-Google-Smtp-Source: AGRyM1uPiyB7rEJDdAsYAVesh6XcxF7m4/NOwgKHx35NtLh0WZv9A8PqKLV1Gu8X5xOooB/DS/0V1C1QSZU= X-Received: from yuzhao.bld.corp.google.com ([2620:15c:183:200:b89c:e10a:466e:cf7d]) (user=yuzhao job=sendgmr) by 2002:a25:390:0:b0:66e:b9c7:b46c with SMTP id 138-20020a250390000000b0066eb9c7b46cmr172371ybd.505.1657144853349; Wed, 06 Jul 2022 15:00:53 -0700 (PDT) Date: Wed, 6 Jul 2022 16:00:11 -0600 In-Reply-To: <20220706220022.968789-1-yuzhao@google.com> Message-Id: <20220706220022.968789-3-yuzhao@google.com> Mime-Version: 1.0 References: <20220706220022.968789-1-yuzhao@google.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog Subject: [PATCH v13 02/14] mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG From: Yu Zhao To: Andrew Morton Cc: Andi Kleen , Aneesh Kumar , Catalin Marinas , Dave Hansen , Hillf Danton , Jens Axboe , Johannes Weiner , Jonathan Corbet , Linus Torvalds , Matthew Wilcox , Mel Gorman , Michael Larabel , Michal Hocko , Mike Rapoport , Peter Zijlstra , Tejun Heo , Vlastimil Babka , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, page-reclaim@google.com, Yu Zhao , Barry Song , Brian Geffon , Jan Alexander Steffens , Oleksandr Natalenko , Steven Barrett , Suleiman Souhlal , Daniel Byrne , Donald Carr , "=?UTF-8?q?Holger=20Hoffst=C3=A4tte?=" , Konstantin Kharlamov , Shuang Zhai , Sofia Trinh , Vaibhav Jain Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some architectures support the accessed bit in non-leaf PMD entries, e.g., x86 sets the accessed bit in a non-leaf PMD entry when using it as part of linear address translation [1]. Page table walkers that clear the accessed bit may use this capability to reduce their search space. Note that: 1. Although an inline function is preferable, this capability is added as a configuration option for consistency with the existing macros. 2. Due to the little interest in other varieties, this capability was only tested on Intel and AMD CPUs. Thanks to the following developers for their efforts [2][3]. Randy Dunlap Stephen Rothwell [1]: Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3 (June 2021), section 4.8 [2] https://lore.kernel.org/r/bfdcc7c8-922f-61a9-aa15-7e7250f04af7@infradea= d.org/ [3] https://lore.kernel.org/r/20220413151513.5a0d7a7e@canb.auug.org.au/ Signed-off-by: Yu Zhao Reviewed-by: Barry Song Acked-by: Brian Geffon Acked-by: Jan Alexander Steffens (heftig) Acked-by: Oleksandr Natalenko Acked-by: Steven Barrett Acked-by: Suleiman Souhlal Tested-by: Daniel Byrne Tested-by: Donald Carr Tested-by: Holger Hoffst=C3=A4tte Tested-by: Konstantin Kharlamov Tested-by: Shuang Zhai Tested-by: Sofia Trinh Tested-by: Vaibhav Jain --- arch/Kconfig | 8 ++++++++ arch/x86/Kconfig | 1 + arch/x86/include/asm/pgtable.h | 3 ++- arch/x86/mm/pgtable.c | 5 ++++- include/linux/pgtable.h | 4 ++-- 5 files changed, 17 insertions(+), 4 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index fcf9a41a4ef5..eaeec187bd6a 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1403,6 +1403,14 @@ config DYNAMIC_SIGFRAME config HAVE_ARCH_NODE_DEV_GROUP bool =20 +config ARCH_HAS_NONLEAF_PMD_YOUNG + bool + help + Architectures that select this option are capable of setting the + accessed bit in non-leaf PMD entries when using them as part of linear + address translations. Page table walkers that clear the accessed bit + may use this capability to reduce their search space. + source "kernel/gcov/Kconfig" =20 source "scripts/gcc-plugins/Kconfig" diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index be0b95e51df6..5715111abe13 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -85,6 +85,7 @@ config X86 select ARCH_HAS_PMEM_API if X86_64 select ARCH_HAS_PTE_DEVMAP if X86_64 select ARCH_HAS_PTE_SPECIAL + select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 select ARCH_HAS_COPY_MC if X86_64 select ARCH_HAS_SET_MEMORY diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.= h index dc5f7d8ef68a..5059799bebe3 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -815,7 +815,8 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) =20 static inline int pmd_bad(pmd_t pmd) { - return (pmd_flags(pmd) & ~_PAGE_USER) !=3D _KERNPG_TABLE; + return (pmd_flags(pmd) & ~(_PAGE_USER | _PAGE_ACCESSED)) !=3D + (_KERNPG_TABLE & ~_PAGE_ACCESSED); } =20 static inline unsigned long pages_to_mb(unsigned long npg) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index a932d7712d85..8525f2876fb4 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -550,7 +550,7 @@ int ptep_test_and_clear_young(struct vm_area_struct *vm= a, return ret; } =20 -#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEA= F_PMD_YOUNG) int pmdp_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { @@ -562,6 +562,9 @@ int pmdp_test_and_clear_young(struct vm_area_struct *vm= a, =20 return ret; } +#endif + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE int pudp_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pud_t *pudp) { diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 8eee31bc9bde..9c57c5cc49c2 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -213,7 +213,7 @@ static inline int ptep_test_and_clear_young(struct vm_a= rea_struct *vma, #endif =20 #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG -#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEA= F_PMD_YOUNG) static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) @@ -234,7 +234,7 @@ static inline int pmdp_test_and_clear_young(struct vm_a= rea_struct *vma, BUILD_BUG(); return 0; } -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG= */ #endif =20 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH --=20 2.37.0.rc0.161.g10f37bed90-goog