Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261979AbUDHQyc (ORCPT ); Thu, 8 Apr 2004 12:54:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262005AbUDHQyc (ORCPT ); Thu, 8 Apr 2004 12:54:32 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.101]:50133 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id S261979AbUDHQya (ORCPT ); Thu, 8 Apr 2004 12:54:30 -0400 Date: Thu, 08 Apr 2004 10:05:42 -0700 From: "Martin J. Bligh" To: Hugh Dickins , Andrew Morton cc: Andi Kleen , colpatch@us.ibm.com, linux-kernel@vger.kernel.org Subject: Re: NUMA API for Linux Message-ID: <5470000.1081443942@flay> In-Reply-To: References: X-Mailer: Mulberry/2.1.2 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1257 Lines: 35 > On Wed, 7 Apr 2004, Andrew Morton wrote: >> >> Your patch takes the CONFIG_NUMA vma from 64 bytes to 68. It would be nice >> to pull those 4 bytes back somehow. > > How significant is this vma size issue? > > anon_vma objrmap will add 20 bytes to each vma (on 32-bit arches): > 8 for prio_tree, 12 for anon_vma linkage in vma, > sometimes another 12 for the anon_vma head itself. Ewwww. Isn't some of that shared most of the time though? > anonmm objrmap adds just the 8 bytes for prio_tree, > remaining overhead 28 bytes per mm. 28 bytes per *mm* is nothing, and I still think the prio_tree is completely unneccesary. Nobody has ever demonstrated a real benchmark that needs it, as far as I recall. > Seems hard on Andi to begrudge him 4. I don't care about the 4 bytes much (other than that the current 64 happens to be a nice size). I just don't see the point in making copies of the binding structure all the time ;-) Refcounts aren't that hard ... didn't Greg do a kref just recently? ... M. - 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/