Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753300AbXFVBgb (ORCPT ); Thu, 21 Jun 2007 21:36:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751303AbXFVBgY (ORCPT ); Thu, 21 Jun 2007 21:36:24 -0400 Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:52108 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751278AbXFVBgX (ORCPT ); Thu, 21 Jun 2007 21:36:23 -0400 Date: Thu, 21 Jun 2007 18:36:21 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Hugh Dickins cc: Nicolas Ferre , ARM Linux Mailing List , Linux Kernel list , Marc Pignat , Andrew Victor , Pierre Ossman , Andrew Morton , Linus Torvalds Subject: Re: Oops in a driver while using SLUB as a SLAB allocator In-Reply-To: Message-ID: References: <467A4532.40301@rfo.atmel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1748 Lines: 48 Maybe this will address the issue on ARM? ARM: Allocate dma pages via the page allocator and not via the slab allocator Slab allocations are not guaranteed to be page aligned and slab allocators may use the page structs for their own purposes. Using the page allocator yields a properly aligned page and also makes the page flushing logic work right. Passing a kmalloced "page" to a flushing function will not work reliably. This will hopefully address the issue with SLUB on ARM. SLUB uses the page->mapping field which is also checked by the flushing logic. The flushing logic expects a normal page and not a slab page. Signed-off-by: Christoph Lameter --- arch/arm/mm/consistent.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: linux-2.6/arch/arm/mm/consistent.c =================================================================== --- linux-2.6.orig/arch/arm/mm/consistent.c 2007-06-21 18:18:15.000000000 -0700 +++ linux-2.6/arch/arm/mm/consistent.c 2007-06-21 18:29:16.000000000 -0700 @@ -277,7 +277,7 @@ dma_alloc_coherent(struct device *dev, s if (arch_is_coherent()) { void *virt; - virt = kmalloc(size, gfp); + virt = get_free_pages(gfp, get_order(size)); if (!virt) return NULL; *handle = virt_to_dma(dev, virt); @@ -364,7 +364,7 @@ void dma_free_coherent(struct device *de WARN_ON(irqs_disabled()); if (arch_is_coherent()) { - kfree(cpu_addr); + free_pages((unsigned long)cpu_addr, get_order(size)); return; } - 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/