From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by kanga.kvack.org (Postfix) with ESMTP id 2A2DF6B0035 for ; Tue, 22 Jul 2014 12:04:28 -0400 (EDT) Received: by mail-pa0-f51.google.com with SMTP id ey11so12366980pad.10 for ; Tue, 22 Jul 2014 09:04:27 -0700 (PDT) Received: from collaborate-mta1.arm.com (fw-tnat.austin.arm.com. [217.140.110.23]) by mx.google.com with ESMTP id ay10si456429pdb.175.2014.07.22.09.04.26 for ; Tue, 22 Jul 2014 09:04:27 -0700 (PDT) Date: Tue, 22 Jul 2014 17:04:08 +0100 From: Catalin Marinas Subject: Re: [PATCHv4 3/5] common: dma-mapping: Introduce common remapping functions Message-ID: <20140722160408.GM2219@arm.com> References: <1404324218-4743-1-git-send-email-lauraa@codeaurora.org> <1404324218-4743-4-git-send-email-lauraa@codeaurora.org> <20140718135349.GB4608@arm.com> <53CD6B1C.2010801@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53CD6B1C.2010801@codeaurora.org> Sender: owner-linux-mm@kvack.org List-ID: To: Laura Abbott Cc: Will Deacon , David Riley , "linux-arm-kernel@lists.infradead.org" , Ritesh Harjain , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" On Mon, Jul 21, 2014 at 08:33:48PM +0100, Laura Abbott wrote: > On 7/18/2014 6:53 AM, Catalin Marinas wrote: > > On Wed, Jul 02, 2014 at 07:03:36PM +0100, Laura Abbott wrote: > >> +void *dma_common_pages_remap(struct page **pages, size_t size, > >> + unsigned long vm_flags, pgprot_t prot, > >> + const void *caller) > >> +{ > >> + struct vm_struct *area; > >> + > >> + area = get_vm_area_caller(size, vm_flags, caller); > >> + if (!area) > >> + return NULL; > >> + > >> + if (map_vm_area(area, prot, &pages)) { > >> + vunmap(area->addr); > >> + return NULL; > >> + } > >> + > >> + return area->addr; > >> +} > > > > Why not just replace this function with vmap()? It is nearly identical. > > With this version, the caller stored and printed via /proc/vmallocinfo > is the actual caller of the DMA API whereas if we just call vmap we > don't get any useful caller information. Going to vmap would change > the existing behavior on ARM so it seems unwise to switch. OK. > Another option is to move this into vmalloc.c and add vmap_caller. Maybe as a subsequent clean-up (once this series gets merged). -- Catalin -- 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