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| author | Steve Capper <steve.capper@linaro.org> | 2014-03-21 10:55:36 +0000 |
|---|---|---|
| committer | Steve Capper <steve.capper@linaro.org> | 2014-08-11 13:28:35 +0100 |
| commit | cb7413c65e80bd4e56759ca99f010be0e526f6f4 (patch) | |
| tree | 06255646d08ddd5940e2dbf6b38c4dc4e9fd26a0 | |
| parent | d6f9fff293f3cd8b4433bc8df7f5a5fc3238cdde (diff) | |
| download | linux-cb7413c65e80bd4e56759ca99f010be0e526f6f4.tar.gz | |
arm64: mm: Enable RCU fast_gup
Activate the RCU fast_gup for ARM64. We also need to force THP splits
to broadcast an IPI s.t. we block in the fast_gup page walker. As THP
splits are comparatively rare, this should not lead to a noticeable
performance degradation.
Some pre-requisite functions pud_write and pud_page are also added.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
| -rw-r--r-- | arch/arm64/Kconfig | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 11 | ||||
| -rw-r--r-- | arch/arm64/mm/flush.c | 19 |
3 files changed, 32 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e03b47cae2b..8d3ad8dec05 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -103,6 +103,9 @@ config GENERIC_CALIBRATE_DELAY config ZONE_DMA def_bool y +config HAVE_RCU_GUP + def_bool y + config ARCH_DMA_ADDR_T_64BIT def_bool y diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index e0ccceb317d..62510f7ca20 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -237,7 +237,13 @@ static inline pmd_t pte_pmd(pte_t pte) #ifdef CONFIG_TRANSPARENT_HUGEPAGE #define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT)) #define pmd_trans_splitting(pmd) pte_special(pmd_pte(pmd)) -#endif +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH +struct vm_area_struct; +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp); +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) @@ -258,6 +264,7 @@ static inline pmd_t pte_pmd(pte_t pte) #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) +#define pud_write(pud) pmd_write(__pmd(pud_val(pud))) #define pud_pfn(pud) (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT) #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)) @@ -345,6 +352,8 @@ static inline pmd_t *pud_page_vaddr(pud_t pud) return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK); } +#define pud_page(pud) pmd_page(__pmd(pud_val(pud))) + #endif /* CONFIG_ARM64_64K_PAGES */ /* to find an entry in a page-table-directory */ diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 0d64089d28b..a177b703aa3 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -104,3 +104,22 @@ EXPORT_SYMBOL(flush_dcache_page); */ EXPORT_SYMBOL(flush_cache_all); EXPORT_SYMBOL(flush_icache_range); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +static void thp_splitting_flush_sync(void *arg) +{ +} + +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + pmd_t pmd = pmd_mksplitting(*pmdp); + VM_BUG_ON(address & ~PMD_MASK); + set_pmd_at(vma->vm_mm, address, pmdp, pmd); + + /* dummy IPI to serialise against fast_gup */ + smp_call_function(thp_splitting_flush_sync, NULL, 1); +} +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |