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=-2.3 required=3.0 tests=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 93B09C432C0 for ; Tue, 3 Dec 2019 11:19:12 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 64FB2206EC for ; Tue, 3 Dec 2019 11:19:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sNdEtWsu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64FB2206EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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=+rbIe6N5Sap/RLAp3xCdVJm/Fn7oIpkwaevnVjFA/E4=; b=sNdEtWsuSgJUqF Tq6NvKOeyON3GnppsJSunJ7dhV1NxG4WWvvzpBNVvU3pb/Hn8lGAqHQpHmDQg//GaDJgLA8IRUq55 xghW+gtTgsl3Y+Od389Bc7FbFBMpWEXFKGJf6QC+XFiDhra1N6AeJe7kfrtfvPAKP3sf5ZKdzpXMn lCXMXm93vBR4ZOHZymstjqP14Zs/rGItLOdvgWuq9alEXBqfX6talbSAyqIboHwGEuZKEXQfJrBgh QePPTU/c+yI7HNpdJriaB5yi1fAQLjVCGuL799Jvvfu3jD1aUiwm8vxCFEkptgKRwok/tyLsdlGL1 Z8ozAa6PLds7MC7VquiQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic6D1-0007KA-Nd; Tue, 03 Dec 2019 11:19:11 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic6Cy-0007JA-1F; Tue, 03 Dec 2019 11:19:09 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C1D9430E; Tue, 3 Dec 2019 03:19:04 -0800 (PST) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.197.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 916673F68E; Tue, 3 Dec 2019 03:19:02 -0800 (PST) Date: Tue, 3 Dec 2019 11:19:00 +0000 From: Catalin Marinas To: Will Deacon Subject: Re: [PATCH v6 3/4] arm64: use both ZONE_DMA and ZONE_DMA32 Message-ID: <20191203111900.GA23522@arrakis.emea.arm.com> References: <20190911182546.17094-1-nsaenzjulienne@suse.de> <20190911182546.17094-4-nsaenzjulienne@suse.de> <20191203101249.GC6815@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191203101249.GC6815@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191203_031908_165760_B56EB2EE X-CRM114-Status: GOOD ( 19.10 ) 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: linux-arm-kernel , Amit Pundir , Florian Fainelli , mbrugger@suse.com, Marc Zyngier , lkml , Bjorn Andersson , linux-mm , Rob Herring , John Stultz , wahrenst@gmx.net, Nicolas Dechense , Marek Szyprowski , Robin Murphy , Christoph Hellwig , Nicolas Saenz Julienne , linux-rpi-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Archived-At: List-Archive: On Tue, Dec 03, 2019 at 10:12:50AM +0000, Will Deacon wrote: > On Mon, Dec 02, 2019 at 10:03:17PM -0800, John Stultz wrote: > > Ok, narrowing it down further, it seems its the following bit from the > > patch: > > > > > @@ -201,13 +212,18 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) > > > struct memblock_region *reg; > > > unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; > > > unsigned long max_dma32 = min; > > > + unsigned long max_dma = min; > > > > > > memset(zone_size, 0, sizeof(zone_size)); > > > > > > - /* 4GB maximum for 32-bit only capable devices */ > > > +#ifdef CONFIG_ZONE_DMA > > > + max_dma = PFN_DOWN(arm64_dma_phys_limit); > > > + zone_size[ZONE_DMA] = max_dma - min; > > > + max_dma32 = max_dma; > > > +#endif > > > #ifdef CONFIG_ZONE_DMA32 > > > max_dma32 = PFN_DOWN(arm64_dma32_phys_limit); > > > - zone_size[ZONE_DMA32] = max_dma32 - min; > > > + zone_size[ZONE_DMA32] = max_dma32 - max_dma; > > > #endif > > > zone_size[ZONE_NORMAL] = max - max_dma32; > > > > > > @@ -219,11 +235,17 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) > > > > > > if (start >= max) > > > continue; > > > - > > > +#ifdef CONFIG_ZONE_DMA > > > + if (start < max_dma) { > > > + unsigned long dma_end = min_not_zero(end, max_dma); > > > + zhole_size[ZONE_DMA] -= dma_end - start; > > > + } > > > +#endif > > > #ifdef CONFIG_ZONE_DMA32 > > > if (start < max_dma32) { > > > - unsigned long dma_end = min(end, max_dma32); > > > - zhole_size[ZONE_DMA32] -= dma_end - start; > > > + unsigned long dma32_end = min(end, max_dma32); > > > + unsigned long dma32_start = max(start, max_dma); > > > + zhole_size[ZONE_DMA32] -= dma32_end - dma32_start; > > > } > > > #endif > > > if (end > max_dma32) { > > > > The zhole_sizes end up being: > > zhole_size: DMA: 67671, DMA32: 1145664 NORMAL: 0 > > > > This seems to be due to dma32_start being calculated as 786432 each > > time - I'm guessing that's the max_dma value. > > Where dma32_end is around 548800, but changes each iteration (so we > > end up subtracting a negative value each pass, growing the size). [...] > Anyway, I've had a go at fixing it below but it's 100% untested. I think > the issue is that your SoC has memblocks contained entirely within the > ZONE_DMA region and we don't cater for that at all when processing the > ZONE_DMA32 region. This seems to be issue, the SoC memory contained withing ZONE_DMA. I managed to reproduce it under KVM/Qemu by reducing the amount of memory given to the guest. You'd also need NUMA disabled to hit this code path. Your proposed change fixes it but I'll send a tested-by on the full patch when it hits the list. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel