From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754399Ab2JIQ6x (ORCPT ); Tue, 9 Oct 2012 12:58:53 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53559 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752084Ab2JIQ6q (ORCPT ); Tue, 9 Oct 2012 12:58:46 -0400 From: Mel Gorman To: Stable Cc: Andi Kleen , Andrew Morton , KOSAKI Motohiro , Dave Jones , Christoph Lameter , Hugh Dickins , LKML , Linux-MM , Mel Gorman Subject: [PATCH 1/5] revert "mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages" Date: Tue, 9 Oct 2012 17:58:37 +0100 Message-Id: <1349801921-16598-2-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.9.2 In-Reply-To: <1349801921-16598-1-git-send-email-mgorman@suse.de> References: <1349801921-16598-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: KOSAKI Motohiro commit 8d34694c1abf29df1f3c7317936b7e3e2e308d9b upstream. Commit 05f144a0d5c2 ("mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages") removed vma->vm_policy updates code but it is the purpose of mbind_range(). Now, mbind_range() is virtually a no-op and while it does not allow memory corruption it is not the right fix. This patch is a revert. [mgorman@suse.de: Edited changelog] Signed-off-by: KOSAKI Motohiro Signed-off-by: Mel Gorman Cc: Christoph Lameter Cc: Josh Boyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman --- mm/mempolicy.c | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4ada3be..92daa26 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -607,6 +607,27 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end, return first; } +/* Apply policy to a single VMA */ +static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) +{ + int err = 0; + struct mempolicy *old = vma->vm_policy; + + pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", + vma->vm_start, vma->vm_end, vma->vm_pgoff, + vma->vm_ops, vma->vm_file, + vma->vm_ops ? vma->vm_ops->set_policy : NULL); + + if (vma->vm_ops && vma->vm_ops->set_policy) + err = vma->vm_ops->set_policy(vma, new); + if (!err) { + mpol_get(new); + vma->vm_policy = new; + mpol_put(old); + } + return err; +} + /* Step 2: apply policy to a range and do splits. */ static int mbind_range(struct mm_struct *mm, unsigned long start, unsigned long end, struct mempolicy *new_pol) @@ -655,23 +676,9 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, if (err) goto out; } - - /* - * Apply policy to a single VMA. The reference counting of - * policy for vma_policy linkages has already been handled by - * vma_merge and split_vma as necessary. If this is a shared - * policy then ->set_policy will increment the reference count - * for an sp node. - */ - pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", - vma->vm_start, vma->vm_end, vma->vm_pgoff, - vma->vm_ops, vma->vm_file, - vma->vm_ops ? vma->vm_ops->set_policy : NULL); - if (vma->vm_ops && vma->vm_ops->set_policy) { - err = vma->vm_ops->set_policy(vma, new_pol); - if (err) - goto out; - } + err = policy_vma(vma, new_pol); + if (err) + goto out; } out: -- 1.7.9.2