Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264628AbUF1Bon (ORCPT ); Sun, 27 Jun 2004 21:44:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264633AbUF1Bon (ORCPT ); Sun, 27 Jun 2004 21:44:43 -0400 Received: from ozlabs.org ([203.10.76.45]:44423 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S264628AbUF1Bok (ORCPT ); Sun, 27 Jun 2004 21:44:40 -0400 Date: Mon, 28 Jun 2004 11:05:24 +1000 From: David Gibson To: Oleg Nesterov Cc: linux-kernel@vger.kernel.org, Andrew Morton , "Chen, Kenneth W" Subject: Re: [PATCH] kill mm_struct.used_hugetlb Message-ID: <20040628010524.GA5006@zax> Mail-Followup-To: David Gibson , Oleg Nesterov , linux-kernel@vger.kernel.org, Andrew Morton , "Chen, Kenneth W" References: <40DD7814.779DEF17@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40DD7814.779DEF17@tv-sign.ru> User-Agent: Mutt/1.5.6+20040523i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1235 Lines: 31 On Sat, Jun 26, 2004 at 05:20:20PM +0400, Oleg Nesterov wrote: > Hello. > > mm_struct.used_hugetlb used to eliminate costly find_vma() > from follow_page(). Now it is used only in ia64 version of > follow_huge_addr(). I know nothing about ia64, but this > REGION_NUMBER() looks simple enough to kill used_hugetlb. > > There is debug version (commented out) of follow_huge_addr() > in i386 which looks at used_hugetlb, but it can work without > this check. > > Am i missed somethimg? Sounds like an excellent idea to me. The find_vma()s were already bogus - no-one used the vma returned by hugepage_vma(), except to check if it was NULL or not. On all archs, whether the address is hugepage or not can be determined from the address, either by walking the pagetables or just by checking the address's range. -- David Gibson | For every complex problem there is a david AT gibson.dropbear.id.au | solution which is simple, neat and | wrong. http://www.ozlabs.org/people/dgibson - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/