From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f72.google.com (mail-it0-f72.google.com [209.85.214.72]) by kanga.kvack.org (Postfix) with ESMTP id C3EA36B0389 for ; Tue, 14 Feb 2017 00:32:28 -0500 (EST) Received: by mail-it0-f72.google.com with SMTP id e137so17123597itc.0 for ; Mon, 13 Feb 2017 21:32:28 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id 128si5904957itx.74.2017.02.13.21.32.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Feb 2017 21:32:28 -0800 (PST) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1E5SrGJ055369 for ; Tue, 14 Feb 2017 00:32:27 -0500 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0b-001b2d01.pphosted.com with ESMTP id 28kjhw3c70-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 14 Feb 2017 00:32:27 -0500 Received: from localhost by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 13 Feb 2017 22:32:26 -0700 From: "Aneesh Kumar K.V" Subject: [PATCH V2 1/2] mm/autonuma: Let architecture override how the write bit should be stashed in a protnone pte. Date: Tue, 14 Feb 2017 11:01:53 +0530 In-Reply-To: <1487050314-3892-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1487050314-3892-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Message-Id: <1487050314-3892-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, Rik van Riel , Mel Gorman , paulus@ozlabs.org, benh@kernel.crashing.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Autonuma preserves the write permission across numa fault to avoid taking a writefault after a numa fault (Commit: b191f9b106ea " mm: numa: preserve PTE write permissions across a NUMA hinting fault"). Architecture can implement protnone in different ways and some may choose to implement that by clearing Read/ Write/Exec bit of pte. Setting the write bit on such pte can result in wrong behaviour. Fix this up by allowing arch to override how to save the write bit on a protnone pte. Acked-By: Michael Neuling Signed-off-by: Aneesh Kumar K.V --- include/asm-generic/pgtable.h | 16 ++++++++++++++++ mm/huge_memory.c | 4 ++-- mm/memory.c | 2 +- mm/mprotect.c | 4 ++-- 4 files changed, 21 insertions(+), 5 deletions(-) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 18af2bcefe6a..b6f3a8a4b738 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -192,6 +192,22 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres } #endif +#ifndef pte_savedwrite +#define pte_savedwrite pte_write +#endif + +#ifndef pte_mk_savedwrite +#define pte_mk_savedwrite pte_mkwrite +#endif + +#ifndef pmd_savedwrite +#define pmd_savedwrite pmd_write +#endif + +#ifndef pmd_mk_savedwrite +#define pmd_mk_savedwrite pmd_mkwrite +#endif + #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT #ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline void pmdp_set_wrprotect(struct mm_struct *mm, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9a6bd6c8d55a..2f0f855ec911 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1300,7 +1300,7 @@ int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd) goto out; clear_pmdnuma: BUG_ON(!PageLocked(page)); - was_writable = pmd_write(pmd); + was_writable = pmd_savedwrite(pmd); pmd = pmd_modify(pmd, vma->vm_page_prot); pmd = pmd_mkyoung(pmd); if (was_writable) @@ -1555,7 +1555,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, entry = pmdp_huge_get_and_clear_notify(mm, addr, pmd); entry = pmd_modify(entry, newprot); if (preserve_write) - entry = pmd_mkwrite(entry); + entry = pmd_mk_savedwrite(entry); ret = HPAGE_PMD_NR; set_pmd_at(mm, addr, pmd, entry); BUG_ON(vma_is_anonymous(vma) && !preserve_write && diff --git a/mm/memory.c b/mm/memory.c index e78bf72f30dd..88c24f89d6d3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3388,7 +3388,7 @@ static int do_numa_page(struct vm_fault *vmf) int target_nid; bool migrated = false; pte_t pte; - bool was_writable = pte_write(vmf->orig_pte); + bool was_writable = pte_savedwrite(vmf->orig_pte); int flags = 0; /* diff --git a/mm/mprotect.c b/mm/mprotect.c index f9c07f54dd62..15f5c174a7c1 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -113,13 +113,13 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, ptent = ptep_modify_prot_start(mm, addr, pte); ptent = pte_modify(ptent, newprot); if (preserve_write) - ptent = pte_mkwrite(ptent); + ptent = pte_mk_savedwrite(ptent); /* Avoid taking write faults for known dirty pages */ if (dirty_accountable && pte_dirty(ptent) && (pte_soft_dirty(ptent) || !(vma->vm_flags & VM_SOFTDIRTY))) { - ptent = pte_mkwrite(ptent); + ptent = pte_mk_savedwrite(ptent); } ptep_modify_prot_commit(mm, addr, pte, ptent); pages++; -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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