From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from cmpxchg.org ([85.214.51.133]:33651 "EHLO cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761086AbZEASPM (ORCPT ); Fri, 1 May 2009 14:15:12 -0400 Date: Fri, 1 May 2009 20:14:49 +0200 From: Johannes Weiner To: Magnus Damm Cc: linux-media@vger.kernel.org, hverkuil@xs4all.nl, linux-mm@kvack.org, lethal@linux-sh.org Subject: Re: [PATCH] videobuf-dma-contig: zero copy USERPTR support V2 Message-ID: <20090501181449.GA8912@cmpxchg.org> References: <20090428090129.17081.782.sendpatchset@rx1.opensource.se> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-media-owner@vger.kernel.org List-ID: On Fri, May 01, 2009 at 12:26:38PM +0900, Magnus Damm wrote: > On Tue, Apr 28, 2009 at 6:01 PM, Magnus Damm wrote: > > This is V2 of the V4L2 videobuf-dma-contig USERPTR zero copy patch. > > I guess the V4L2 specific bits are pretty simple. > > As for the minor mm modifications below, > > > --- 0001/mm/memory.c > > +++ work/mm/memory.c    2009-04-28 14:56:43.000000000 +0900 > > @@ -3009,7 +3009,6 @@ int in_gate_area_no_task(unsigned long a > > > >  #endif /* __HAVE_ARCH_GATE_AREA */ > > > > -#ifdef CONFIG_HAVE_IOREMAP_PROT > >  int follow_phys(struct vm_area_struct *vma, > >                unsigned long address, unsigned int flags, > >                unsigned long *prot, resource_size_t *phys) > > Is it ok with the memory management guys to always build follow_phys()? AFAICS, pte_pgprot is only defined on three architectures that have the config symbol above set. It shouldn't compile on the others. I have a patch that factors out follow_pte and builds follow_pfn and follow_phys on top of that. I can send it monday, no access to it from here right now. Then we can keep follow_phys private to this configuration. Hannes