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,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 8E74FC433E0 for ; Wed, 22 Jul 2020 14:31:22 +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 59FDF20709 for ; Wed, 22 Jul 2020 14:31:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Q4UUQPF8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59FDF20709 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=VzdD/2MIyzTijYMpwXngu44TtBl4NQSTduMPTd5CFAM=; b=Q4UUQPF88zCZctR+poCELJlo+ OOS6Wk/rdSGKfWLc2f4hsh2iLR216xKc42HNoJUklxDUk37Fk3oHul+p29T+CNYy8KnxGCUSmfO1W wDomkCELT+WIXyLeQKSHFoMmfpG0g+sg6zth3sXbDN3Wc+F+nykGKtWmdrQzCEJ7tVtPDXYEyAur4 W9oeUpquANDTHqTvigBqYfEM6rqdFVU+Nr703GcNwcS76K3Q68l615gNJruk3xY1JoHqvwK+gCzpD MmY0VE3/5xjJIjAquHNwp1uZ+PFYgsQzdQjerab/ETl3J/0e5YlknSVo/s2sxbCjSSD7kB++NKU0J /Rffrnwag==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyFkj-0004VT-Ny; Wed, 22 Jul 2020 14:29:49 +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 1jyFkg-0004Uj-Uu for linux-arm-kernel@lists.infradead.org; Wed, 22 Jul 2020 14:29:47 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id B599868B05; Wed, 22 Jul 2020 16:29:43 +0200 (CEST) Date: Wed, 22 Jul 2020 16:29:43 +0200 From: Christoph Hellwig To: Barry Song Subject: Re: [PATCH v3 1/2] dma-direct: provide the ability to reserve per-numa CMA Message-ID: <20200722142943.GB17658@lst.de> References: <20200628111251.19108-1-song.bao.hua@hisilicon.com> <20200628111251.19108-2-song.bao.hua@hisilicon.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200628111251.19108-2-song.bao.hua@hisilicon.com> 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-20200722_102947_110774_55BCD606 X-CRM114-Status: GOOD ( 14.25 ) 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, Steve Capper , robin.murphy@arm.com, Jonathan Cameron , linuxarm@huawei.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Nicolas Saenz Julienne , ganapatrao.kulkarni@cavium.com, Andrew Morton , Mike Rapoport , will@kernel.org, hch@lst.de, 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 Sun, Jun 28, 2020 at 11:12:50PM +1200, Barry Song wrote: > struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) > { > size_t count = size >> PAGE_SHIFT; > struct page *page = NULL; > struct cma *cma = NULL; > + int nid = dev ? dev_to_node(dev) : NUMA_NO_NODE; > + bool alloc_from_pernuma = false; > + > + if ((count <= 1) && !(dev && dev->cma_area)) > + return NULL; > > if (dev && dev->cma_area) > cma = dev->cma_area; > - else if (count > 1) > + else if ((nid != NUMA_NO_NODE) && dma_contiguous_pernuma_area[nid] > + && !(gfp & (GFP_DMA | GFP_DMA32))) { > + cma = dma_contiguous_pernuma_area[nid]; > + alloc_from_pernuma = true; > + } else { > cma = dma_contiguous_default_area; > + } I find the function rather confusing now. What about something like (this relies on the fact that dev should never be NULL in the DMA API) struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) { size_t cma_align = min_t(size_t, get_order(size), CONFIG_CMA_ALIGNMENT); size_t count = size >> PAGE_SHIFT; if (gfpflags_allow_blocking(gfp)) return NULL; gfp &= __GFP_NOWARN; if (dev->cma_area) return cma_alloc(dev->cma_area, count, cma_align, gfp); if (count <= 1) return NULL; if (IS_ENABLED(CONFIG_PERNODE_CMA) && !(gfp & (GFP_DMA | GFP_DMA32)) { int nid = dev_to_node(dev); struct cma *cma = dma_contiguous_pernuma_area[nid]; struct page *page; if (cma) { page = cma_alloc(cma, count, cma_align, gfp); if (page) return page; } } return cma_alloc(dma_contiguous_default_area, count, cma_align, gfp); } > + /* > + * otherwise, page is from either per-numa cma or default cma > + */ > + int nid = page_to_nid(page); > + > + if (nid != NUMA_NO_NODE) { > + if (cma_release(dma_contiguous_pernuma_area[nid], page, > + PAGE_ALIGN(size) >> PAGE_SHIFT)) > + return; > + } > + > + if (cma_release(dma_contiguous_default_area, page, How can page_to_nid ever return NUMA_NO_NODE? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel