From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) (using TLSv1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4E54C1A0C62 for ; Thu, 4 Dec 2014 22:24:41 +1100 (AEDT) From: Mel Gorman To: Andrew Morton Subject: [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing Date: Thu, 4 Dec 2014 11:24:25 +0000 Message-Id: <1417692273-27170-3-git-send-email-mgorman@suse.de> In-Reply-To: <1417692273-27170-1-git-send-email-mgorman@suse.de> References: <1417692273-27170-1-git-send-email-mgorman@suse.de> Cc: Rik van Riel , LinuxPPC-dev , Hugh Dickins , Linux Kernel , Linux-MM , Ingo Molnar , Paul Mackerras , Aneesh Kumar , Sasha Levin , Dave Jones , Linus Torvalds , Kirill Shutemov , Mel Gorman List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is a preparatory patch that introduces protnone helpers for automatic NUMA balancing. Signed-off-by: Mel Gorman Acked-by: Linus Torvalds Acked-by: Aneesh Kumar K.V Tested-by: Sasha Levin --- arch/powerpc/include/asm/pgtable.h | 16 ++++++++++++++++ arch/x86/include/asm/pgtable.h | 16 ++++++++++++++++ include/asm-generic/pgtable.h | 20 ++++++++++++++++++++ 3 files changed, 52 insertions(+) diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index a8805fe..7b889a3 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -39,6 +39,22 @@ static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); } #ifdef CONFIG_NUMA_BALANCING +/* + * These work without NUMA balancing but the kernel does not care. See the + * comment in include/asm-generic/pgtable.h . On powerpc, this will only + * work for user pages and always return true for kernel pages. + */ +static inline int pte_protnone(pte_t pte) +{ + return (pte_val(pte) & + (_PAGE_PRESENT | _PAGE_USER)) == _PAGE_PRESENT; +} + +static inline int pmd_protnone(pmd_t pmd) +{ + return pte_protnone(pmd_pte(pmd)); +} + static inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_NUMA_MASK; diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 081d6f4..2e25780 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -502,6 +502,22 @@ static inline int pmd_present(pmd_t pmd) _PAGE_NUMA); } +#ifdef CONFIG_NUMA_BALANCING +/* + * These work without NUMA balancing but the kernel does not care. See the + * comment in include/asm-generic/pgtable.h + */ +static inline int pte_protnone(pte_t pte) +{ + return pte_flags(pte) & _PAGE_PROTNONE; +} + +static inline int pmd_protnone(pmd_t pmd) +{ + return pmd_flags(pmd) & _PAGE_PROTNONE; +} +#endif /* CONFIG_NUMA_BALANCING */ + static inline int pmd_none(pmd_t pmd) { /* Only check low word on 32-bit platforms, since it might be diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 177d597..d497d08 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -688,6 +688,26 @@ static inline int pmd_trans_unstable(pmd_t *pmd) #endif } +#ifndef CONFIG_NUMA_BALANCING +/* + * Technically a PTE can be PROTNONE even when not doing NUMA balancing but + * the only case the kernel cares is for NUMA balancing and is only ever set + * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked + * _PAGE_PROTNONE so by by default, implement the helper as "always no". It + * is the responsibility of the caller to distinguish between PROT_NONE + * protections and NUMA hinting fault protections. + */ +static inline int pte_protnone(pte_t pte) +{ + return 0; +} + +static inline int pmd_protnone(pmd_t pmd) +{ + return 0; +} +#endif /* CONFIG_NUMA_BALANCING */ + #ifdef CONFIG_NUMA_BALANCING /* * _PAGE_NUMA distinguishes between an unmapped page table entry, an entry that -- 2.1.2