From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp08.in.ibm.com (e28smtp08.in.ibm.com [122.248.162.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp08.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 89E1F2C00A4 for ; Thu, 23 May 2013 02:58:29 +1000 (EST) Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 May 2013 22:21:12 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 4CED1394004D for ; Wed, 22 May 2013 22:28:25 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r4MGwJvj3736030 for ; Wed, 22 May 2013 22:28:19 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r4MGwMws020890 for ; Thu, 23 May 2013 02:58:23 +1000 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org, dwg@au1.ibm.com Subject: [PATCH -V9 20/20] powerpc: split hugepage when using subpage protection Date: Wed, 22 May 2013 22:27:52 +0530 Message-Id: <1369241872-15700-21-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-Reply-To: <1369241872-15700-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1369241872-15700-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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; -- 1.8.1.2