Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964881AbWJJRxQ (ORCPT ); Tue, 10 Oct 2006 13:53:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964866AbWJJRxQ (ORCPT ); Tue, 10 Oct 2006 13:53:16 -0400 Received: from smtp.osdl.org ([65.172.181.4]:63161 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S964881AbWJJRxP (ORCPT ); Tue, 10 Oct 2006 13:53:15 -0400 Date: Tue, 10 Oct 2006 10:52:36 -0700 From: Andrew Morton To: Nick Piggin Cc: Christoph Hellwig , Linux Memory Management , Linux Kernel Subject: Re: [patch 3/3] mm: fault handler to replace nopage and populate Message-Id: <20061010105236.2ef0268b.akpm@osdl.org> In-Reply-To: <20061010121327.GA2431@wotan.suse.de> References: <20061007105758.14024.70048.sendpatchset@linux.site> <20061007105853.14024.95383.sendpatchset@linux.site> <20061010121003.GA19322@infradead.org> <20061010121327.GA2431@wotan.suse.de> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1887 Lines: 44 On Tue, 10 Oct 2006 14:13:27 +0200 Nick Piggin wrote: > On Tue, Oct 10, 2006 at 01:10:03PM +0100, Christoph Hellwig wrote: > > On Sat, Oct 07, 2006 at 03:06:32PM +0200, Nick Piggin wrote: > > > +/* > > > + * fault_data is filled in the the pagefault handler and passed to the > > > + * vma's ->fault function. That function is responsible for filling in > > > + * 'type', which is the type of fault if a page is returned, or the type > > > + * of error if NULL is returned. > > > + */ > > > +struct fault_data { > > > + struct vm_area_struct *vma; > > > + unsigned long address; > > > + pgoff_t pgoff; > > > + unsigned int flags; > > > + > > > + int type; > > > +}; > > > > > > /* > > > * These are the virtual MM functions - opening of an area, closing and > > > @@ -203,6 +221,7 @@ extern pgprot_t protection_map[16]; > > > struct vm_operations_struct { > > > void (*open)(struct vm_area_struct * area); > > > void (*close)(struct vm_area_struct * area); > > > + struct page * (*fault)(struct fault_data * data); > > > > Please pass the vma as an explicit first argument so that all vm_operations > > operate on a vma. It's also much cleaner to have the separate between the > > the object operated on (the vma) and all the fault details (struct fault_data). > > Hmm... I agree it is more consistent, but OTOH if we're passing a > structure I thought it may as well just go in there. But I will > change unless anyone comes up with an objection. I'd agree that it's more attractive to have the vma* in the argument list, but it presumably adds runtime cost: cycles and stack depth. I don't how much though. - 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/