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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 BEBD9C433E0 for ; Tue, 28 Jul 2020 12:24:08 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 8BF68206D4 for ; Tue, 28 Jul 2020 12:24:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="dXemHEXh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8BF68206D4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Myhd014jRRK/R4puLxxrrl3l1uXJRDBvAlERNGGpVGo=; b=dXemHEXhx6nGL0SSfXib0dVZb POLzQtGE7WNh88Jeq6/d6/o4u7ElrmgdZ0PKm4JVJ3tOFmWavOJL9cblaA1IPWa3hsElfiQmD38sG 2TM5qOEvcLwTLFTRmL3iKLIzq+CDS0aGshTjBFsuzFqp4O6lm53EsY25HVJr+R2IepS4WOmEZL7+S XcBrpIBuSEMXHBz+lPK5G2v2eQyoyYRU46a/+8kl78kW+T5bnFLQMe/6UYUxNPBJH6I1fm+OJeEpI YY4nh8ws+441CeVqokUDYC+j6p0BsbEPSYIq8NlSrFe/fusUgtEjwFgwDNtc1Xeu3UY3zMVWBU01S u5BiCjRKQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0Od7-0007e6-Te; Tue, 28 Jul 2020 12:22:49 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0Od5-0007dD-QN for linux-arm-kernel@lists.infradead.org; Tue, 28 Jul 2020 12:22:48 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id E2E8B68B05; Tue, 28 Jul 2020 14:22:44 +0200 (CEST) Date: Tue, 28 Jul 2020 14:22:44 +0200 From: Christoph Hellwig To: "Song Bao Hua (Barry Song)" Subject: Re: [PATCH v4 1/2] dma-direct: provide the ability to reserve per-numa CMA Message-ID: <20200728122244.GA3639@lst.de> References: <20200723131344.41472-1-song.bao.hua@hisilicon.com> <20200723131344.41472-2-song.bao.hua@hisilicon.com> <20200728115231.GA793@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200728_082247_969331_48681DE7 X-CRM114-Status: GOOD ( 23.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "catalin.marinas@arm.com" , Mike Rapoport , Steve Capper , "robin.murphy@arm.com" , Jonathan Cameron , Linuxarm , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , Nicolas Saenz Julienne , "Zengtao \(B\)" , "ganapatrao.kulkarni@cavium.com" , Andrew Morton , huangdaode , "will@kernel.org" , Christoph Hellwig , "linux-arm-kernel@lists.infradead.org" , "m.szyprowski@samsung.com" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jul 28, 2020 at 12:19:03PM +0000, Song Bao Hua (Barry Song) wrote: > I am sorry I haven't got your point yet. Do you mean something like the below? > > arch/arm64/Kconfig: > config CMDLINE > string "Default kernel command string" > - default "" > + default "pernuma_cma=16M" > help > Provide a set of default command-line options at build time by > entering them here. As a minimum, you should specify the the > root device (e.g. root=/dev/nfs). Yes. > A background of the current code is that Linux distributions can usually use arch/arm64/configs/defconfig > directly to build kernel. cmdline can be easily ignored during the generation of Linux distributions. I've not actually heard of a distro shipping defconfig yet.. > > > if a way to expose this in the device tree might be useful, but people > > more familiar with the device tree and the arm code will have to chime > > in on that. > > Not sure if it is an useful user case as we are using ACPI but not device tree since it is an ARM64 > server with NUMA. Well, than maybe ACPI experts need to chime in on this. > > This seems to have lost the dma_contiguous_default_area NULL check. > > cma_alloc() is doing the check by returning NULL if cma is NULL. > > struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, > bool no_warn) > { > ... > if (!cma || !cma->count) > return NULL; > } > > But I agree here the code can check before calling cma_alloc_aligned. Oh, indeed. Please split the removal of the NULL check in to a prep patch then. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel