From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755776Ab2HJNQr (ORCPT ); Fri, 10 Aug 2012 09:16:47 -0400 Received: from cantor2.suse.de ([195.135.220.15]:40883 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752988Ab2HJNQq (ORCPT ); Fri, 10 Aug 2012 09:16:46 -0400 Date: Fri, 10 Aug 2012 15:16:43 +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: <20120810131643.GC1425@dhcp22.suse.cz> References: <20120803133235.GA8434@dhcp22.suse.cz> <20120810094825.GA1440@dhcp22.suse.cz> <20120810122730.GA1425@dhcp22.suse.cz> <20120810125102.GB1425@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 [CCing Kamezawa and David] On Fri 10-08-12 20:53:36, Hillf Danton wrote: > On Fri, Aug 10, 2012 at 8:51 PM, Michal Hocko wrote: > > On Fri 10-08-12 20:37:20, Hillf Danton wrote: > >> On Fri, Aug 10, 2012 at 8:27 PM, Michal Hocko wrote: > >> > > >> > I guess you mean unmap_ref_private and that has been changed by you > >> > (0c176d5 mm: hugetlb: fix pgoff computation when unmapping page from > >> > vma)... I was wrong at that time when giving my Reviewed-by. The patch > >> > didn't break anything because you still find all relevant vmas because > >> > vma_hugecache_offset just provides a smaller index which is still within > >> > boundaries. > >> > >> No, as shown by the log message of 0c176d52b, that fix was > >> triggered by (vma->vm_pgoff >> PAGE_SHIFT), thus I dont see > >> what you really want to revert. > > > > fix for that would be a part of the revert of course. > > > > Fine, go ahead ;) there you go --- >>From 973187e9bad72181f4563a675ca64235f8612a2a 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. Cc: Hillf Danton Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki 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