From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 8D5806B0055 for ; Thu, 13 Aug 2009 16:33:03 -0400 (EDT) Date: Thu, 13 Aug 2009 22:32:59 +0200 (CEST) From: Julia Lawall Subject: Re: question about nommu.c In-Reply-To: <20090813195738.GA8686@linux-sh.org> Message-ID: References: <20090813195738.GA8686@linux-sh.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Paul Mundt Cc: linux-mm@kvack.org List-ID: On Fri, 14 Aug 2009, Paul Mundt wrote: > On Thu, Aug 13, 2009 at 09:41:38PM +0200, Julia Lawall wrote: > > The function vmalloc_user in the file mm/nommu.c contains the following > > code: > > > > struct vm_area_struct *vma; > > ... > > if (vma) > > vma->vm_flags |= VM_USERMAP; > > > > The constant VM_USERMAP, however, is elsewhere used in a structure of type > > vm_struct, not vm_area_struct. Furthermore, the value of VM_USERMAP is 8, > > which is the same as the value of VM_SHARED (define in mm.h), which is > > elsewhere used with a vm_area_struct structure. Is this occurrence of > > VM_USERMAP correct? Or should it be VM_SHARED? Or should it be something > > else? > > > Yes, this is currently broken, albeit generally harmless. I've been > working on cleaning this up, but have not gotten around to posting > patches yet. > > Part of this requires building on top of the infrastructure we have in > place with the vm_regions to layer a proper vmap implementation on top > of, which should in turn restore some meaning to the vmlist and permit > struct vm_struct to be used on nommu properly. > > At the moment this is not a big problem as it doesn't really impact > anything, it's more regarding future directions for the nommu memory > management code. OK, perhaps I should just let you clean it up in a more general way then. julia -- 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