diff options
| author | Bibo Mao <maobibo@loongson.cn> | 2020-05-27 05:25:19 +0300 |
|---|---|---|
| committer | Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2020-05-27 14:06:40 +0300 |
| commit | 44bf431b47b4298d8aaba7b02d0ad29fc609a03c (patch) | |
| tree | abdc24c53f8a9c2a7c283e799a44c29db145d780 /include/asm-generic | |
| parent | 7df676974359f927056b882e10a5b24d2033169b (diff) | |
| download | linux-44bf431b47b4298d8aaba7b02d0ad29fc609a03c.tar.xz | |
mm/memory.c: Add memory read privilege on page fault handling
Here add pte_sw_mkyoung function to make page readable on MIPS
platform during page fault handling. This patch improves page
fault latency about 10% on my MIPS machine with lmbench
lat_pagefault case.
It is noop function on other arches, there is no negative
influence on those architectures.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/pgtable.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index fa5c73ff8226..b5278ec627db 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -244,6 +244,22 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres } #endif +/* + * On some architectures hardware does not set page access bit when accessing + * memory page, it is responsibilty of software setting this bit. It brings + * out extra page fault penalty to track page access bit. For optimization page + * access bit can be set during all page fault flow on these arches. + * To be differentiate with macro pte_mkyoung, this macro is used on platforms + * where software maintains page access bit. + */ +#ifndef pte_sw_mkyoung +static inline pte_t pte_sw_mkyoung(pte_t pte) +{ + return pte; +} +#define pte_sw_mkyoung pte_sw_mkyoung +#endif + #ifndef pte_savedwrite #define pte_savedwrite pte_write #endif |