From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx174.postini.com [74.125.245.174]) by kanga.kvack.org (Postfix) with SMTP id 1B1AF6B0117 for ; Tue, 26 Jun 2012 09:06:39 -0400 (EDT) Message-ID: <4FE9B3B4.1050305@redhat.com> Date: Tue, 26 Jun 2012 09:05:56 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH -mm v2 01/11] mm: track free size between VMAs in VMA rbtree References: <1340315835-28571-1-git-send-email-riel@surriel.com> <1340315835-28571-2-git-send-email-riel@surriel.com> <1340359115.18025.57.camel@twins> <4FE47D0E.3000804@redhat.com> <1340374439.18025.75.camel@twins> <4FE48054.5090407@redhat.com> <1340375872.18025.77.camel@twins> <4FE4922D.8070501@surriel.com> <1340652578.21991.18.camel@twins> <4FE8DD80.9040108@redhat.com> <1340699507.21991.32.camel@twins> In-Reply-To: <1340699507.21991.32.camel@twins> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Rik van Riel , linux-mm@kvack.org, akpm@linux-foundation.org, aarcange@redhat.com, minchan@gmail.com, kosaki.motohiro@gmail.com, andi@firstfloor.org, hannes@cmpxchg.org, mel@csn.ul.ie, linux-kernel@vger.kernel.org, danielfsantos@att.net On 06/26/2012 04:31 AM, Peter Zijlstra wrote: > If you look at your patch 1, __vma_unlink has an adjust_free_gap() right > next to the rb_augment_erase(), vma_adjust() has 3 adjust_free_gap() > calls right next to each other. > > All these will do an entire path walk back to the root. I would think we > could save quite a bit of updating by not having them all walk back to > the root. No point in re-computing the top levels if you know the next > update will change them again anyway. The problem is, unless we look at the augmented data at rotate time, we do not know when it is safe to stop iterating up the tree. -- All rights reversed -- 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