From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757491AbYE2PBT (ORCPT ); Thu, 29 May 2008 11:01:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754042AbYE2PBB (ORCPT ); Thu, 29 May 2008 11:01:01 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:49402 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753895AbYE2PBA (ORCPT ); Thu, 29 May 2008 11:01:00 -0400 Date: Thu, 29 May 2008 08:00:58 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: David Howells cc: Pekka Enberg , Paul Mundt , LKML , cooloney@kernel.org, akpm@linux-foundation.org, mpm@selenic.com Subject: Re: [PATCH] nommu: fix kobjsize() for SLOB and SLUB In-Reply-To: <29611.1212066517@redhat.com> Message-ID: References: <20080528153648.GA27783@linux-sh.org> <483DBA85.2060502@cs.helsinki.fi> <483DBFC3.1070108@cs.helsinki.fi> <29611.1212066517@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 May 2008, David Howells wrote: > > Could the nommu people either tell us what this is all about? Or junk the > > code. This looks very wrong. > > ELF-FDPIC is currently using kobjsize() so that it can expand the heap/stack > segment to fill up the entirety of its allocation. It's probably worth > dropping that, though. > > NOMMU mmap() is using kobjsize()/ksize() to keep track of the number of bytes > allocated and the amount of dead space. We can probably ditch that too. > > However, fs/proc/task_nommu.c uses kobjsize() quite a bit to determine how > much metadata space a process is carrying around. We could just use sizeof(), > I suppose, and not bother calculating the slack. The nagging question here is: Why is page->private used in kobjsize()? A special heap/stack setup?