From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from moutng.kundenserver.de ([212.227.126.186]:62608 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751834Ab2A2UwQ convert rfc822-to-8bit (ORCPT ); Sun, 29 Jan 2012 15:52:16 -0500 From: Arnd Bergmann To: Andrew Morton Subject: Re: [PATCHv19 00/15] Contiguous Memory Allocator Date: Sun, 29 Jan 2012 20:51:46 +0000 Cc: Marek Szyprowski , 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, Michal Nazarewicz , Kyungmin Park , Russell King , KAMEZAWA Hiroyuki , Daniel Walker , Mel Gorman , Jesse Barker , Jonathan Corbet , Shariq Hasnain , Chunsang Jeong , Dave Hansen , Benjamin Gaignard References: <1327568457-27734-1-git-send-email-m.szyprowski@samsung.com> <201201261531.40551.arnd@arndb.de> <20120127162624.40cba14e.akpm@linux-foundation.org> In-Reply-To: <20120127162624.40cba14e.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Message-Id: <201201292051.46297.arnd@arndb.de> Sender: linux-media-owner@vger.kernel.org List-ID: On Saturday 28 January 2012, Andrew Morton wrote: > These patches don't seem to have as many acked-bys and reviewed-bys as > I'd expect. Given the scope and duration of this, it would be useful > to gather these up. But please ensure they are real ones - people > sometimes like to ack things without showing much sign of having > actually read them. I reviewed early versions of this patch set and had a lot of comments on the interfaces that were exposed to device drivers and platform maintainers. All of the comments were addressed back then and I gave an Acked-by. I assume that it was dropped in subsequent versions because the implementation changed significantly since, but I'm still happy with the way this looks to the user, in particular that it is practically invisible because all users just go through the dma mapping API instead of the horrors that were used in the original patches. >>From an ARM architecture perspective, we have come to the point (some versions ago) where we actually require the CMA patchset for correctness, even on IOMMU based systems because it avoids some nasty corner cases with pages that are both in the linear kernel mapping and in an uncached mapping for DMA: We know that the code we are using in mainline is broken on ARMv6 and later and that CMA fixes that problem. I'm not the right person to judge the memory management code changes, others need to comment on that. Aside from that: Acked-by: Arnd Bergmann Arnd