From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx135.postini.com [74.125.245.135]) by kanga.kvack.org (Postfix) with SMTP id E5F1C6B005C for ; Wed, 30 May 2012 15:17:34 -0400 (EDT) Date: Wed, 30 May 2012 14:17:29 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH 1/6] Revert "mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages" In-Reply-To: <1338368529-21784-2-git-send-email-kosaki.motohiro@gmail.com> Message-ID: References: <1338368529-21784-1-git-send-email-kosaki.motohiro@gmail.com> <1338368529-21784-2-git-send-email-kosaki.motohiro@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Dave Jones , Mel Gorman , Linus Torvalds , stable@vger.kernel.org, hughd@google.com, Andrew Morton , KOSAKI Motohiro On Wed, 30 May 2012, kosaki.motohiro@gmail.com wrote: > From: KOSAKI Motohiro > > commit 05f144a0d5 removed vma->vm_policy updates code and it is a purpose of > mbind_range(). Now, mbind_range() is virtually no-op. no-op function don't > makes any bugs, I agree. but maybe it is not right fix. I dont really understand the changelog. But to restore the policy_vma() is the right thing to do since there are potential multiple use cases where we want to apply a policy to a vma. Proposed new changelog: Commit 05f144a0d5 folded policy_vma() into mbind_range(). There are other use cases of policy_vma(*) though and so revert a piece of that commit in order to have a policy_vma() function again. > @@ -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. > - */ You are dropping the nice comments by Mel that explain the refcounting. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org