From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751784Ab1FVHcW (ORCPT ); Wed, 22 Jun 2011 03:32:22 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:35699 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750945Ab1FVHcU (ORCPT ); Wed, 22 Jun 2011 03:32:20 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:content-type:to:cc:subject:references:date:mime-version :content-transfer-encoding:from:message-id:in-reply-to:user-agent; b=tStewBfXgydNXD3tCRhrwgzn8hhOURp6bJG8NmHoHd+gKn5LiQhs+HlbEQPjNdYGLr +3V3crmjLvyOqvX1kNCBwcKjU7LcTtiPU13Y3H+IH2kBpv11uVf/1ZAlfQTlq+vajfAq ZvZ3E4J8NHVoK4hixWElfPI7ID8y+S1+vmalc= Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes To: linaro-mm-sig@lists.linaro.org, "Hans Verkuil" Cc: "Arnd Bergmann" , linux-arm-kernel@lists.infradead.org, "'Daniel Walker'" , linux-mm@kvack.org, "'Mel Gorman'" , linux-kernel@vger.kernel.org, "'Jesse Barker'" , "'Kyungmin Park'" , "'Ankita Garg'" , "'Andrew Morton'" , linux-media@vger.kernel.org, "'KAMEZAWA Hiroyuki'" Subject: Re: [Linaro-mm-sig] [PATCH 08/10] mm: cma: Contiguous Memory Allocator added References: <1307699698-29369-1-git-send-email-m.szyprowski@samsung.com> <000501cc2b2b$789a54b0$69cefe10$%szyprowski@samsung.com> <201106150937.18524.arnd@arndb.de> <201106220903.31065.hverkuil@xs4all.nl> Date: Wed, 22 Jun 2011 09:32:13 +0200 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Michal Nazarewicz" Message-ID: In-Reply-To: <201106220903.31065.hverkuil@xs4all.nl> User-Agent: Opera Mail/11.10 (Linux) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 22 Jun 2011 09:03:30 +0200, Hans Verkuil wrote: > What I was wondering about is how this patch series changes the > allocation in case it can't allocate from the CMA pool. Will it > attempt to fall back to a 'normal' allocation? Unless Marek changed something since I wrote the code, which I doubt, if CMA cannot obtain memory from CMA region, it will fail. Part of the reason is that CMA lacks the knowledge where to allocate memory from. For instance, with the case of several memory banks, it does not know which memory bank to allocate from. It is, in my opinion, a task for a higher level functions (read: DMA layer) to try another mechanism if CMA fails. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michal "mina86" Nazarewicz (o o) ooo +----------ooO--(_)--Ooo-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id 2B7C090015D for ; Wed, 22 Jun 2011 03:32:22 -0400 (EDT) Received: by ywb26 with SMTP id 26so277458ywb.14 for ; Wed, 22 Jun 2011 00:32:20 -0700 (PDT) Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Subject: Re: [Linaro-mm-sig] [PATCH 08/10] mm: cma: Contiguous Memory Allocator added References: <1307699698-29369-1-git-send-email-m.szyprowski@samsung.com> <000501cc2b2b$789a54b0$69cefe10$%szyprowski@samsung.com> <201106150937.18524.arnd@arndb.de> <201106220903.31065.hverkuil@xs4all.nl> Date: Wed, 22 Jun 2011 09:32:13 +0200 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Michal Nazarewicz" Message-ID: In-Reply-To: <201106220903.31065.hverkuil@xs4all.nl> Sender: owner-linux-mm@kvack.org List-ID: To: linaro-mm-sig@lists.linaro.org, Hans Verkuil Cc: Arnd Bergmann , linux-arm-kernel@lists.infradead.org, 'Daniel Walker' , linux-mm@kvack.org, 'Mel Gorman' , linux-kernel@vger.kernel.org, 'Jesse Barker' , 'Kyungmin Park' , 'Ankita Garg' , 'Andrew Morton' , linux-media@vger.kernel.org, 'KAMEZAWA Hiroyuki' On Wed, 22 Jun 2011 09:03:30 +0200, Hans Verkuil wrote: > What I was wondering about is how this patch series changes the > allocation in case it can't allocate from the CMA pool. Will it > attempt to fall back to a 'normal' allocation? Unless Marek changed something since I wrote the code, which I doubt, if CMA cannot obtain memory from CMA region, it will fail. Part of the reason is that CMA lacks the knowledge where to allocate memory from. For instance, with the case of several memory banks, it does not know which memory bank to allocate from. It is, in my opinion, a task for a higher level functions (read: DMA layer) to try another mechanism if CMA fails. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michal "mina86" Nazarewicz (o o) ooo +----------ooO--(_)--Ooo-- -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: mina86@mina86.com (Michal Nazarewicz) Date: Wed, 22 Jun 2011 09:32:13 +0200 Subject: [Linaro-mm-sig] [PATCH 08/10] mm: cma: Contiguous Memory Allocator added In-Reply-To: <201106220903.31065.hverkuil@xs4all.nl> References: <1307699698-29369-1-git-send-email-m.szyprowski@samsung.com> <000501cc2b2b$789a54b0$69cefe10$%szyprowski@samsung.com> <201106150937.18524.arnd@arndb.de> <201106220903.31065.hverkuil@xs4all.nl> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 22 Jun 2011 09:03:30 +0200, Hans Verkuil wrote: > What I was wondering about is how this patch series changes the > allocation in case it can't allocate from the CMA pool. Will it > attempt to fall back to a 'normal' allocation? Unless Marek changed something since I wrote the code, which I doubt, if CMA cannot obtain memory from CMA region, it will fail. Part of the reason is that CMA lacks the knowledge where to allocate memory from. For instance, with the case of several memory banks, it does not know which memory bank to allocate from. It is, in my opinion, a task for a higher level functions (read: DMA layer) to try another mechanism if CMA fails. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michal "mina86" Nazarewicz (o o) ooo +----------ooO--(_)--Ooo--