From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751571AbaJDMgo (ORCPT ); Sat, 4 Oct 2014 08:36:44 -0400 Received: from cantor2.suse.de ([195.135.220.15]:45688 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750959AbaJDMgn (ORCPT ); Sat, 4 Oct 2014 08:36:43 -0400 Date: Sat, 4 Oct 2014 14:36:37 +0200 From: Jean Delvare To: LKML Cc: Joonsoo Kim , Greg Kroah-Hartman Subject: [PATCH] CMA: Document cma=0 Message-ID: <20141004143637.26eb9a11@endymion.delvare> Organization: SUSE Linux X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It isn't obvious that CMA can be disabled on the kernel's command line, so document it. Signed-off-by: Jean Delvare Cc: Joonsoo Kim Cc: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 3 ++- drivers/base/Kconfig | 3 +++ 2 files changed, 5 insertions(+), 1 deletion(-) --- linux-3.17-rc7.orig/Documentation/kernel-parameters.txt 2014-09-23 13:19:06.644838292 +0200 +++ linux-3.17-rc7/Documentation/kernel-parameters.txt 2014-10-04 14:10:03.257579721 +0200 @@ -656,7 +656,8 @@ bytes respectively. Such letter suffixes Sets the size of kernel global memory area for contiguous memory allocations and optionally the placement constraint by the physical address range of - memory allocations. For more information, see + memory allocations. A value of 0 disables CMA + altogether. For more information, see include/linux/dma-contiguous.h cmo_free_hint= [PPC] Format: { yes | no } --- linux-3.17-rc7.orig/drivers/base/Kconfig 2014-09-12 16:23:14.911353676 +0200 +++ linux-3.17-rc7/drivers/base/Kconfig 2014-10-04 13:41:37.672347240 +0200 @@ -231,6 +231,9 @@ config DMA_CMA to allocate big physically-contiguous blocks of memory for use with hardware components that do not support I/O map nor scatter-gather. + You can disable CMA by specifying "cma=0" on the kernel's command + line. + For more information see . If unsure, say "n". -- Jean Delvare SUSE L3 Support