From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751368Ab2HLJbQ (ORCPT ); Sun, 12 Aug 2012 05:31:16 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49945 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750838Ab2HLJbP (ORCPT ); Sun, 12 Aug 2012 05:31:15 -0400 Date: Sun, 12 Aug 2012 11:31:11 +0200 From: Michal Hocko To: Hillf Danton Cc: Mel Gorman , Andrew Morton , Linux-MM , LKML , KAMEZAWA Hiroyuki , David Rientjes Subject: Re: [patch] hugetlb: correct page offset index for sharing pmd Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun 12-08-12 12:08:21, Hillf Danton wrote: > On Fri, Aug 10, 2012 at 9:48 PM, Michal Hocko wrote: > > > It's been compile tested because it only restores the previous code with > > a simple and obvious bug fix. > > It helps more if you elaborate on such a simple and obvious bug and > enrich your change log accordingly? Hmmm, to be honest I really don't care much about this change. It is just that your previous patch (0c176d5) made the code more confusing and this aims at fixing that. But anyway. I will post this to Andrew unless somebody has any objections. --- >>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. 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