From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Capper Subject: [PATCH V3 6/6] arm64: mm: Enable RCU fast_gup Date: Thu, 28 Aug 2014 15:45:07 +0100 Message-ID: <1409237107-24228-7-git-send-email-steve.capper@linaro.org> References: <1409237107-24228-1-git-send-email-steve.capper@linaro.org> Return-path: In-Reply-To: <1409237107-24228-1-git-send-email-steve.capper@linaro.org> Sender: owner-linux-mm@kvack.org To: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux@arm.linux.org.uk, linux-arch@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Cc: will.deacon@arm.com, gary.robertson@linaro.org, christoffer.dall@linaro.org, peterz@infradead.org, anders.roxell@linaro.org, dann.frazier@canonical.com, mark.rutland@arm.com, mgorman@suse.de, Steve Capper List-Id: linux-arch.vger.kernel.org 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 Tested-by: Dann Frazier Acked-by: Catalin Marinas --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/pgtable.h | 21 ++++++++++++++++++++- arch/arm64/mm/flush.c | 15 +++++++++++++++ 3 files changed, 38 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index ce9062b..435305e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -108,6 +108,9 @@ config GENERIC_CALIBRATE_DELAY config ZONE_DMA def_bool y +config HAVE_GENERIC_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 ffe1ba0..6d81471 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -239,6 +239,16 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #define __HAVE_ARCH_PTE_SPECIAL +static inline pte_t pud_pte(pud_t pud) +{ + return __pte(pud_val(pud)); +} + +static inline pmd_t pud_pmd(pud_t pud) +{ + return __pmd(pud_val(pud)); +} + static inline pte_t pmd_pte(pmd_t pmd) { return __pte(pmd_val(pmd)); @@ -256,7 +266,13 @@ 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))) @@ -277,6 +293,7 @@ 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) pte_write(pud_pte(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)) @@ -376,6 +393,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr); } +#define pud_page(pud) pmd_page(pud_pmd(pud)) + #endif /* CONFIG_ARM64_PGTABLE_LEVELS > 2 */ #if CONFIG_ARM64_PGTABLE_LEVELS > 3 diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 0d64089..2d5fd47 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -104,3 +104,18 @@ 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 +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 */ + kick_all_cpus_sync(); +} +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -- 1.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:53846 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751607AbaH1Opf (ORCPT ); Thu, 28 Aug 2014 10:45:35 -0400 Received: by mail-wg0-f44.google.com with SMTP id m15so848358wgh.3 for ; Thu, 28 Aug 2014 07:45:32 -0700 (PDT) From: Steve Capper Subject: [PATCH V3 6/6] arm64: mm: Enable RCU fast_gup Date: Thu, 28 Aug 2014 15:45:07 +0100 Message-ID: <1409237107-24228-7-git-send-email-steve.capper@linaro.org> In-Reply-To: <1409237107-24228-1-git-send-email-steve.capper@linaro.org> References: <1409237107-24228-1-git-send-email-steve.capper@linaro.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux@arm.linux.org.uk, linux-arch@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Cc: will.deacon@arm.com, gary.robertson@linaro.org, christoffer.dall@linaro.org, peterz@infradead.org, anders.roxell@linaro.org, dann.frazier@canonical.com, mark.rutland@arm.com, mgorman@suse.de, Steve Capper Message-ID: <20140828144507.U1vhuE3tyZ0ogH3F9sc4dUuY410TEH95gh4T_FtWsBY@z> 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 Tested-by: Dann Frazier Acked-by: Catalin Marinas --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/pgtable.h | 21 ++++++++++++++++++++- arch/arm64/mm/flush.c | 15 +++++++++++++++ 3 files changed, 38 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index ce9062b..435305e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -108,6 +108,9 @@ config GENERIC_CALIBRATE_DELAY config ZONE_DMA def_bool y +config HAVE_GENERIC_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 ffe1ba0..6d81471 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -239,6 +239,16 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #define __HAVE_ARCH_PTE_SPECIAL +static inline pte_t pud_pte(pud_t pud) +{ + return __pte(pud_val(pud)); +} + +static inline pmd_t pud_pmd(pud_t pud) +{ + return __pmd(pud_val(pud)); +} + static inline pte_t pmd_pte(pmd_t pmd) { return __pte(pmd_val(pmd)); @@ -256,7 +266,13 @@ 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))) @@ -277,6 +293,7 @@ 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) pte_write(pud_pte(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)) @@ -376,6 +393,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr); } +#define pud_page(pud) pmd_page(pud_pmd(pud)) + #endif /* CONFIG_ARM64_PGTABLE_LEVELS > 2 */ #if CONFIG_ARM64_PGTABLE_LEVELS > 3 diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 0d64089..2d5fd47 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -104,3 +104,18 @@ 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 +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 */ + kick_all_cpus_sync(); +} +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -- 1.9.3