-From f8b663bbfa30af5515e222fd74df20ea4e8393a2 Mon Sep 17 00:00:00 2001
+From 493de1c4b0f2cd909169401da8c445f6c8a7e29d Mon Sep 17 00:00:00 2001
From: Yu Zhao <yuzhao@google.com>
-Date: Sat, 26 Sep 2020 21:17:18 -0600
-Subject: [PATCH 02/10] mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
+Date: Sun, 18 Sep 2022 01:59:59 -0600
+Subject: [PATCH 02/29] mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
-Some architectures support the accessed bit on non-leaf PMD entries,
-e.g., x86_64 sets the accessed bit on a non-leaf PMD entry when using
-it as part of linear address translation [1]. As an optimization, page
-table walkers who are interested in the accessed bit can skip the PTEs
-under a non-leaf PMD entry if the accessed bit is cleared on this PMD
-entry.
+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.
-Although an inline function may be preferable, this capability is
-added as a configuration option to look consistent when used with the
-existing macros.
+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 <rdunlap@infradead.org>
+ Stephen Rothwell <sfr@canb.auug.org.au>
[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@infradead.org/
+[3] https://lore.kernel.org/r/20220413151513.5a0d7a7e@canb.auug.org.au/
+Link: https://lkml.kernel.org/r/20220918080010.2920238-3-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
+Reviewed-by: Barry Song <baohua@kernel.org>
+Acked-by: Brian Geffon <bgeffon@google.com>
+Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
+Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
+Acked-by: Steven Barrett <steven@liquorix.net>
+Acked-by: Suleiman Souhlal <suleiman@google.com>
+Tested-by: Daniel Byrne <djbyrne@mtu.edu>
+Tested-by: Donald Carr <d@chaos-reins.com>
+Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
-Change-Id: I1a17be3ae926f721f7b17ea1539e5c39e8c4f9a8
+Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
+Tested-by: Sofia Trinh <sofia.trinh@edi.works>
+Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
+Cc: Andi Kleen <ak@linux.intel.com>
+Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
+Cc: Catalin Marinas <catalin.marinas@arm.com>
+Cc: Dave Hansen <dave.hansen@linux.intel.com>
+Cc: Hillf Danton <hdanton@sina.com>
+Cc: Jens Axboe <axboe@kernel.dk>
+Cc: Johannes Weiner <hannes@cmpxchg.org>
+Cc: Jonathan Corbet <corbet@lwn.net>
+Cc: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Matthew Wilcox <willy@infradead.org>
+Cc: Mel Gorman <mgorman@suse.de>
+Cc: Miaohe Lin <linmiaohe@huawei.com>
+Cc: Michael Larabel <Michael@MichaelLarabel.com>
+Cc: Michal Hocko <mhocko@kernel.org>
+Cc: Mike Rapoport <rppt@kernel.org>
+Cc: Mike Rapoport <rppt@linux.ibm.com>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Qi Zheng <zhengqi.arch@bytedance.com>
+Cc: Tejun Heo <tj@kernel.org>
+Cc: Vlastimil Babka <vbabka@suse.cz>
+Cc: Will Deacon <will@kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
- arch/Kconfig | 9 +++++++++
+ 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, 18 insertions(+), 4 deletions(-)
+ 5 files changed, 17 insertions(+), 4 deletions(-)
+diff --git a/arch/Kconfig b/arch/Kconfig
+index 5987363b41c2..62d55b7ccca1 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
-@@ -1295,6 +1295,15 @@ config ARCH_HAS_ELFCORE_COMPAT
+@@ -1295,6 +1295,14 @@ config ARCH_HAS_ELFCORE_COMPAT
config ARCH_HAS_PARANOID_L1D_FLUSH
bool
+config ARCH_HAS_NONLEAF_PMD_YOUNG
+ bool
-+ depends on PGTABLE_LEVELS > 2
+ help
-+ Architectures that select this are able to set the accessed bit on
-+ non-leaf PMD entries in addition to leaf PTE entries where pages are
-+ mapped. For them, page table walkers that clear the accessed bit may
-+ stop at non-leaf PMD entries if they do not see the accessed bit.
++ 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"
source "scripts/gcc-plugins/Kconfig"
+diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
+index a08ce6360382..38e1d231d52a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -84,6 +84,7 @@ 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 X86_64
++ 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 3908780fc408..01a1763123ff 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
-@@ -817,7 +817,8 @@ static inline unsigned long pmd_page_vad
+@@ -817,7 +817,8 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
static inline int pmd_bad(pmd_t pmd)
{
}
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 3481b35cb4ec..a224193d84bf 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_
+@@ -550,7 +550,7 @@ int ptep_test_and_clear_young(struct vm_area_struct *vma,
return ret;
}
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_
+@@ -562,6 +562,9 @@ int pmdp_test_and_clear_young(struct vm_area_struct *vma,
return ret;
}
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 2f1188980baf..e6889556e0bf 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
-@@ -212,7 +212,7 @@ static inline int ptep_test_and_clear_yo
+@@ -212,7 +212,7 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
#endif
#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
pmd_t *pmdp)
-@@ -233,7 +233,7 @@ static inline int pmdp_test_and_clear_yo
+@@ -233,7 +233,7 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
BUILD_BUG();
return 0;
}
#endif
#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
+--
+2.40.0
+
projects / openwrt / openwrt.git / blobdiff