From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx166.postini.com [74.125.245.166]) by kanga.kvack.org (Postfix) with SMTP id AD29C6B006E for ; Mon, 13 Aug 2012 08:10:42 -0400 (EDT) Received: by vbkv13 with SMTP id v13so4193772vbk.14 for ; Mon, 13 Aug 2012 05:10:41 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20120812093110.GB18057@dhcp22.suse.cz> References: <20120810094825.GA1440@dhcp22.suse.cz> <20120810122730.GA1425@dhcp22.suse.cz> <20120810125102.GB1425@dhcp22.suse.cz> <20120810131643.GC1425@dhcp22.suse.cz> <20120810134811.GD1425@dhcp22.suse.cz> <20120812093110.GB18057@dhcp22.suse.cz> Date: Mon, 13 Aug 2012 20:10:41 +0800 Message-ID: Subject: Re: [patch] hugetlb: correct page offset index for sharing pmd From: Hillf Danton Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Mel Gorman , Andrew Morton , Linux-MM , LKML , KAMEZAWA Hiroyuki , David Rientjes On Sun, Aug 12, 2012 at 5:31 PM, Michal Hocko wrote: > From d07b88a70ee1dbcc96502c48cde878931e7deb38 Mon Sep 17 00:00:00 2001 > From: Michal Hocko > Date: Fri, 10 Aug 2012 15:03:07 +0200 > Subject: [PATCH] hugetlb: do not use vma_hugecache_offset for > vma_prio_tree_foreach > > 0c176d5 (mm: hugetlb: fix pgoff computation when unmapping page > from vma) fixed pgoff calculation but it has replaced it by > vma_hugecache_offset which is not approapriate for offsets used for > vma_prio_tree_foreach because that one expects index in page units > rather than in huge_page_shift. What if another case of vma_prio_tree_foreach in try_to_unmap_file is correct? > Using vma_hugecache_offset is not incorrect because the pgoff will fit > into the same vmas but it is confusing so the standard PAGE_SHIFT based > index calculation is used instead. > > Cc: Hillf Danton > Cc: Mel Gorman > Cc: KAMEZAWA Hiroyuki > Cc: Andrea Arcangeli > Cc: David Rientjes > Signed-off-by: Michal Hocko > --- > mm/hugetlb.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index c39e4be..a74ea31 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -2462,7 +2462,8 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, > * from page cache lookup which is in HPAGE_SIZE units. > */ > address = address & huge_page_mask(h); > - pgoff = vma_hugecache_offset(h, vma, address); > + pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + > + vma->vm_pgoff; > mapping = vma->vm_file->f_dentry->d_inode->i_mapping; > > /* > -- > 1.7.10.4 > > > -- > Michal Hocko > SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org