]> www.infradead.org Git - users/jedix/linux-maple.git/commit
mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
authorYu Zhao <yuzhao@google.com>
Thu, 14 Apr 2022 19:16:54 +0000 (12:16 -0700)
committerLiam R. Howlett <Liam.Howlett@oracle.com>
Thu, 14 Apr 2022 21:49:53 +0000 (17:49 -0400)
commit98706e7f113d685a6e71845fca981a87d0ca1cf0
treeedd08a17bd9a1b123a3f2b3abe9f8fc3c9310095
parentefcc7369d8d6774d2c2b48d918f76c898fa13690
mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG

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.

[1]: Intel 64 and IA-32 Architectures Software Developer's Manual
     Volume 3 (June 2021), section 4.8

Link: https://lkml.kernel.org/r/20220407031525.2368067-3-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>
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: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
arch/Kconfig
arch/x86/Kconfig
arch/x86/include/asm/pgtable.h
arch/x86/mm/pgtable.c
include/linux/pgtable.h