Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751886AbWJIShB (ORCPT ); Mon, 9 Oct 2006 14:37:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751890AbWJIShB (ORCPT ); Mon, 9 Oct 2006 14:37:01 -0400 Received: from smtprelay01.ispgateway.de ([80.67.18.13]:45787 "EHLO smtprelay01.ispgateway.de") by vger.kernel.org with ESMTP id S1751886AbWJIShA (ORCPT ); Mon, 9 Oct 2006 14:37:00 -0400 From: Ingo Oeser To: Benjamin Herrenschmidt Subject: Re: User switchable HW mappings & cie Date: Mon, 9 Oct 2006 20:36:47 +0200 User-Agent: KMail/1.9.3 Cc: Thomas =?iso-8859-15?q?Hellstr=F6m?= , linux-mm@kvack.org, Linux Kernel list , Hugh Dickins , Arnd Bergmann , Linus Torvalds , Nick Piggin References: <1160347065.5926.52.camel@localhost.localdomain> <452A35FF.50009@tungstengraphics.com> <1160394662.10229.30.camel@localhost.localdomain> In-Reply-To: <1160394662.10229.30.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200610092036.50010.ioe-lkml@rameria.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1362 Lines: 38 Hi all, On Monday, 9. October 2006 13:51, Benjamin Herrenschmidt wrote: > > One problem that occurs is that the rule for ptes with non-backing > > struct pages > > Which I think was introduced in 2.6.16: > > > > pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT) > > > > cannot be honored, at least not with the DRM memory manager, since the > > graphics object will be associated with a vma and not the underlying > > physical address. User space will have vma->vm_pgoff as a handle to the > > object, which may move around in graphics memory. > > That's a problem with VM_PFNMAP set indeed. get_user_pages() is a > non-issue with VM_IO set too but I'm not sure about other code path that > might try to hit here... though I think we don't hit that if MAP_SHARED, > Nick ? Istn't this just a non-linear PFN mapping, you are describing here? Nick: Cant your new fault consolidation code handle that? AFAICS your new .fault handler just gets the vma and pgoff and install the matching PTE via install_THINGIE() or vm_insert_THINGIE() Or do I miss sth. here? Regards Ingo Oeser - 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/