From mboxrd@z Thu Jan 1 00:00:00 1970 From: vinmenon@codeaurora.org (Vinayak Menon) Date: Tue, 28 Nov 2017 10:37:50 +0530 Subject: [PATCH 2/2] arm64: add faultaround mm hook In-Reply-To: <1511845670-12133-1-git-send-email-vinmenon@codeaurora.org> References: <1511845670-12133-1-git-send-email-vinmenon@codeaurora.org> Message-ID: <1511845670-12133-2-git-send-email-vinmenon@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The ptes produced by faultaround feature are by default young and that is found to cause page reclaim issues [1]. But making the ptes old results in a unixbench regression for some architectures [2]. But arm64 doesn't show the regression. unixbench shell8 scores (5 runs min, max, avg): Base: (741,748,744) With this patch: (739,748,743) Add a faultaround mm hook to make the faultaround ptes old only for arm64. [1] https://lkml.kernel.org/r/1460992636-711-1-git-send-email-vinmenon at codeaurora.org [2] https://marc.info/?l=linux-kernel&m=146582237922378&w=2 Signed-off-by: Vinayak Menon --- arch/arm64/include/asm/Kbuild | 1 - arch/arm64/include/asm/mm-arch-hooks.h | 20 ++++++++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/mm-arch-hooks.h diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index e63d0a8..0043f7c 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -13,7 +13,6 @@ generic-y += kmap_types.h generic-y += local.h generic-y += local64.h generic-y += mcs_spinlock.h -generic-y += mm-arch-hooks.h generic-y += msi.h generic-y += preempt.h generic-y += qrwlock.h diff --git a/arch/arm64/include/asm/mm-arch-hooks.h b/arch/arm64/include/asm/mm-arch-hooks.h new file mode 100644 index 0000000..b34d730 --- /dev/null +++ b/arch/arm64/include/asm/mm-arch-hooks.h @@ -0,0 +1,20 @@ +#ifndef _ASM_MM_ARCH_HOOKS_H +#define _ASM_MM_ARCH_HOOKS_H + +#ifdef CONFIG_ARM64_HW_AFDBM +static inline void arch_faultaround_pte_mkold(struct vm_fault *vmf) +{ + if (vmf->address != vmf->fault_address) + vmf->flags |= FAULT_FLAG_MKOLD; + else + vmf->flags &= ~FAULT_FLAG_MKOLD; +} +#else +static inline void arch_faultaround_pte_mkold(struct vm_fault *vmf) +{ +} +#endif + +#define arch_faultaround_pte_mkold arch_faultaround_pte_mkold + +#endif /* _ASM_MM_ARCH_HOOKS_H */ -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation