From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 98C446B004D for ; Fri, 20 Mar 2009 16:31:37 -0400 (EDT) Subject: Re: PATCH: Introduce struct vma_link_info From: Peter Zijlstra In-Reply-To: <20090320103438.08e67358@doriath.conectiva> References: <20090320103438.08e67358@doriath.conectiva> Content-Type: text/plain Date: Fri, 20 Mar 2009 21:36:29 +0100 Message-Id: <1237581389.4667.130.camel@laptop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: "Luiz Fernando N. Capitulino" Cc: akpm@linux-foundation.org, riel@redhat.com, mingo@elte.hu, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Fri, 2009-03-20 at 10:34 -0300, Luiz Fernando N. Capitulino wrote: > Andrew, > > Currently find_vma_prepare() and low-level VMA functions (eg. __vma_link()) > require callers to provide three parameters to return/pass "link" information > (pprev, rb_link and rb_parent): > > static struct vm_area_struct * > find_vma_prepare(struct mm_struct *mm, unsigned long addr, > struct vm_area_struct **pprev, struct rb_node ***rb_link, > struct rb_node ** rb_parent); > > With this patch callers can pass a struct vma_link_info instead: > > static struct vm_area_struct * > find_vma_prepare(struct mm_struct *mm, unsigned long addr, > struct vma_link_info *link_info); > > The code gets simpler and it should be better because less variables > are pushed into the stack/registers. As shown by the following > kernel build test: > > kernel real user sys > > 2.6.29-rc8-vanilla 1136.64 1033.38 82.88 > 2.6.29-rc8-linfo 1135.07 1032.44 82.92 > > I have also ran hackbench, but I can't understand why its result > indicates a regression: > > kernel Avarage of three runs (25 processes groups) > > 2.6.29.rc8-vanilla 2.03 > 2.6.29.rc8-linfo 2.12 > > Rik has said to me that this could be inside error margin. So, I'm > submitting the patch for inclusion. > > Signed-off-by: Luiz Fernando N. Capitulino I'd rather we look into using the threaded RB-tree to get rid of all this prev crap. -- 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