From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9ACEBC433E0 for ; Wed, 8 Jul 2020 15:35:17 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 78E4B20720 for ; Wed, 8 Jul 2020 15:35:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78E4B20720 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 4D1BF87CD1; Wed, 8 Jul 2020 15:35:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nz5O3G-3BLJH; Wed, 8 Jul 2020 15:35:16 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 0F29887CC5; Wed, 8 Jul 2020 15:35:16 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 026F9C0893; Wed, 8 Jul 2020 15:35:16 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id C8F9DC016F for ; Wed, 8 Jul 2020 15:35:14 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id C4963896BA for ; Wed, 8 Jul 2020 15:35:14 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0zRM8Fxw5pT2 for ; Wed, 8 Jul 2020 15:35:13 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by hemlock.osuosl.org (Postfix) with ESMTPS id 886ED896B8 for ; Wed, 8 Jul 2020 15:35:13 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 45C5168B05; Wed, 8 Jul 2020 17:35:09 +0200 (CEST) Date: Wed, 8 Jul 2020 17:35:09 +0200 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH] dma-pool: use single atomic pool for both DMA zones Message-ID: <20200708153509.GA26743@lst.de> References: <20200707122804.21262-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200707122804.21262-1-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: linux-kernel@vger.kernel.org, jeremy.linton@arm.com, iommu@lists.linux-foundation.org, linux-rpi-kernel@lists.infradead.org, David Rientjes , Robin Murphy , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Jul 07, 2020 at 02:28:04PM +0200, Nicolas Saenz Julienne wrote: > When allocating atomic DMA memory for a device, the dma-pool core > queries __dma_direct_optimal_gfp_mask() to check which atomic pool to > use. It turns out the GFP flag returned is only an optimistic guess. > The pool selected might sometimes live in a zone higher than the > device's view of memory. > > As there isn't a way to grantee a mapping between a device's DMA > constraints and correct GFP flags this unifies both DMA atomic pools. > The resulting pool is allocated in the lower DMA zone available, if any, > so as for devices to always get accessible memory while having the > flexibility of using dma_pool_kernel for the non constrained ones. > > Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask") > Reported-by: Jeremy Linton > Suggested-by: Robin Murphy > Signed-off-by: Nicolas Saenz Julienne Hmm, this is not what I expected from the previous thread. I thought we'd just use one dma pool based on runtime available of the zones.. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu