Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946082Ab2JYOJm (ORCPT ); Thu, 25 Oct 2012 10:09:42 -0400 Received: from mail.free-electrons.com ([88.190.12.23]:34957 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945971Ab2JYOJj (ORCPT ); Thu, 25 Oct 2012 10:09:39 -0400 Date: Thu, 25 Oct 2012 16:09:28 +0200 From: Thomas Petazzoni To: Arnd Bergmann Cc: Gregory CLEMENT , Jason Cooper , Andrew Lunn , linux-arm-kernel@lists.infradead.org, Olof Johansson , Ben Dooks , Ian Molton , Nicolas Pitre , Lior Amsalem , Maen Suleiman , Tawfik Bayouk , Shadi Ammouri , "Eran Ben-Avi" , Yehuda Yitschak , Nadav Haklai , Ike Pan , Jani Monoses , Chris Van Hoof , Dan Frazier , Leif Lindholm , Jon Masters , David Marlin , Sebastian Hesselbarth , linux-kernel@vger.kernel.org, Marek Szyprowski Subject: Re: [PATCH 1/2] arm: mvebu: increase atomic coherent pool size for armada 370/XP Message-ID: <20121025160928.53daf18a@skate> In-Reply-To: <201210251346.41596.arnd@arndb.de> References: <1351086561-13569-1-git-send-email-gregory.clement@free-electrons.com> <201210251127.36960.arnd@arndb.de> <20121025134352.16a8ef81@skate> <201210251346.41596.arnd@arndb.de> Organization: Free Electrons X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; x86_64-pc-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 Content-Length: 1201 Lines: 29 On Thu, 25 Oct 2012 13:46:41 +0000, Arnd Bergmann wrote: > > Seems like the driver is too lazy and allocates everything coherent > > to avoid the hassle of doing dma_map/dma_unmap operations when > > needed, but I haven't looked in details at the driver yet to see if > > it would be possible to switch those DMA coherent allocations into > > non-coherent allocations + appropriate calls to the DMA operations. > > Using coherent allocations is fine, I was wondering whether they need > to be atomic or not. You're raising a good point here: all the dma_pool_alloc() allocations done by sata_mv are GFP_KERNEL. So why are we having problems with the /atomic/ coherent pool size? Is it the libata core that's doing GFP_ATOMIC DMA coherent allocations. It doesn't seem so. Something's odd. Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/