From patchwork Thu Jun 20 09:00:25 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 252821 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 322D82C1014 for ; Thu, 20 Jun 2013 19:09:28 +1000 (EST) Received: from e23smtp02.au.ibm.com (e23smtp02.au.ibm.com [202.81.31.144]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp02.au.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 7C3752C0323 for ; Thu, 20 Jun 2013 19:01:36 +1000 (EST) Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 20 Jun 2013 18:52:07 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 9524F2BB0050 for ; Thu, 20 Jun 2013 19:01:34 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5K8kpbJ47579158 for ; Thu, 20 Jun 2013 18:46:51 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r5K91XWK002051 for ; Thu, 20 Jun 2013 19:01:33 +1000 Received: from skywalker.in.ibm.com (skywalker.in.ibm.com [9.124.35.148]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r5K91CxP032675; Thu, 20 Jun 2013 19:01:32 +1000 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org Subject: [PATCH -V11 13/15] powerpc: split hugepage when using subpage protection Date: Thu, 20 Jun 2013 14:30:25 +0530 Message-Id: <1371718827-15065-14-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1371718827-15065-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1371718827-15065-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062008-5490-0000-0000-000003AE6774 Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: "Aneesh Kumar K.V" We find all the overlapping vma and mark them such that we don't allocate hugepage in that range. Also we split existing huge page so that the normal page hash can be invalidated and new page faulted in with new protection bits. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/mm/subpage-prot.c | 48 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c index 7c415dd..aa74acb 100644 --- a/arch/powerpc/mm/subpage-prot.c +++ b/arch/powerpc/mm/subpage-prot.c @@ -130,6 +130,53 @@ static void subpage_prot_clear(unsigned long addr, unsigned long len) up_write(&mm->mmap_sem); } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static int subpage_walk_pmd_entry(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct vm_area_struct *vma = walk->private; + split_huge_page_pmd(vma, addr, pmd); + return 0; +} + +static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr, + unsigned long len) +{ + struct vm_area_struct *vma; + struct mm_walk subpage_proto_walk = { + .mm = mm, + .pmd_entry = subpage_walk_pmd_entry, + }; + + /* + * We don't try too hard, we just mark all the vma in that range + * VM_NOHUGEPAGE and split them. + */ + vma = find_vma(mm, addr); + /* + * If the range is in unmapped range, just return + */ + if (vma && ((addr + len) <= vma->vm_start)) + return; + + while (vma) { + if (vma->vm_start >= (addr + len)) + break; + vma->vm_flags |= VM_NOHUGEPAGE; + subpage_proto_walk.private = vma; + walk_page_range(vma->vm_start, vma->vm_end, + &subpage_proto_walk); + vma = vma->vm_next; + } +} +#else +static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr, + unsigned long len) +{ + return; +} +#endif + /* * Copy in a subpage protection map for an address range. * The map has 2 bits per 4k subpage, so 32 bits per 64k page. @@ -168,6 +215,7 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) return -EFAULT; down_write(&mm->mmap_sem); + subpage_mark_vma_nohuge(mm, addr, len); for (limit = addr + len; addr < limit; addr = next) { next = pmd_addr_end(addr, limit); err = -ENOMEM;