From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754798Ab2BEOdW (ORCPT ); Sun, 5 Feb 2012 09:33:22 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:33753 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753857Ab2BEOdP convert rfc822-to-8bit (ORCPT ); Sun, 5 Feb 2012 09:33:15 -0500 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes To: "Marek Szyprowski" , "Hillf Danton" Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org, "Kyungmin Park" , "Russell King" , "Andrew Morton" , "KAMEZAWA Hiroyuki" Subject: Re: [PATCH 12/15] drivers: add Contiguous Memory Allocator References: <1328271538-14502-1-git-send-email-m.szyprowski@samsung.com> <1328271538-14502-13-git-send-email-m.szyprowski@samsung.com> Date: Sun, 05 Feb 2012 15:33:08 +0100 MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT From: "Michal Nazarewicz" Message-ID: In-Reply-To: User-Agent: Opera Mail/11.61 (Linux) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 05 Feb 2012 05:25:40 +0100, Hillf Danton wrote: > Without boot mem reservation, what is the successful rate of CMA to > serve requests of 1MiB, 2MiB, 4MiB and 8MiB chunks? CMA will work as long as you manage to get some pageblocks marked as MIGRATE_CMA and move all non-movable pages away. You might try and get it done after system has booted but we have not tried nor tested it. Reservation at boot time lets us make sure that the portion of memory we are grabbing has no unmovable pages. You might still and use alloc_contig_pages() on its own (even without MIGRATE_CMA) but that would require additional code which would look for a region of memory that could be used (ie. that does not have unmovable pages in it). That in fact was what Kamezawa's code was doing. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz (o o) ooo +------------------ooO--(_)--Ooo--