From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 808C2900194 for ; Wed, 22 Jun 2011 09:39:56 -0400 (EDT) From: Arnd Bergmann Subject: Re: [Linaro-mm-sig] [PATCH 08/10] mm: cma: Contiguous =?iso-8859-1?q?Memory=09Allocator?= added Date: Wed, 22 Jun 2011 15:39:23 +0200 References: <1307699698-29369-1-git-send-email-m.szyprowski@samsung.com> <201106221442.20848.arnd@arndb.de> <003701cc30de$7a159710$6e40c530$%szyprowski@samsung.com> In-Reply-To: <003701cc30de$7a159710$6e40c530$%szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201106221539.24044.arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: Marek Szyprowski Cc: 'Hans Verkuil' , 'Daniel Walker' , 'Jesse Barker' , 'Mel Gorman' , 'KAMEZAWA Hiroyuki' , linux-kernel@vger.kernel.org, 'Michal Nazarewicz' , linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, 'Kyungmin Park' , 'Ankita Garg' , 'Andrew Morton' , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org On Wednesday 22 June 2011, Marek Szyprowski wrote: > Sounds really good, but it might be really hard to implemnt, at least for > CMA, because it needs to tweak parameters of memory management internal > structures very early, when buddy allocator has not been activated yet. Why that? I would expect you can do the same that hugepages (used to) do and just attempt high-order allocations. If they succeed, you can add them as a CMA region and free them again, into the movable set of pages, otherwise you just fail the request from user space when the memory is already fragmented. > > These essentially fight over the same memory (though things are slightly > > different with dynamic hugepages), and they all face the same basic problem > > of getting as much for themselves without starving the other three. > > I'm not sure we can solve all such issues in the first version. Maybe we should > first have each of the above fully working in mainline separately and then > start the integration works. Yes, makes sense. We just need to be careful not to introduce user-visible interfaces that we cannot change any more in the process. Arnd -- 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