FROMLIST: 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://lore.kernel.org/r/20220309021230.721028-3-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>
Bug: 227651406
Signed-off-by:
Kalesh Singh <kaleshsingh@google.com>
Change-Id: I73f84a21fd315192eaa3e6443334ed1bccb4e99e
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