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=-2.2 required=3.0 tests=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 00654CA9ECF for ; Thu, 31 Oct 2019 15:51:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B45702087F for ; Thu, 31 Oct 2019 15:51:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B45702087F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5D07A6B0003; Thu, 31 Oct 2019 11:51:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 581CC6B0005; Thu, 31 Oct 2019 11:51:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 46EFE6B0007; Thu, 31 Oct 2019 11:51:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0174.hostedemail.com [216.40.44.174]) by kanga.kvack.org (Postfix) with ESMTP id 2126A6B0003 for ; Thu, 31 Oct 2019 11:51:52 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id CC8435DE0 for ; Thu, 31 Oct 2019 15:51:51 +0000 (UTC) X-FDA: 76104520422.16.cook23_102422e44094a X-HE-Tag: cook23_102422e44094a X-Filterd-Recvd-Size: 3669 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Thu, 31 Oct 2019 15:51:50 +0000 (UTC) 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 B2CF41F1; Thu, 31 Oct 2019 08:51:49 -0700 (PDT) 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 AFB3B3F71E; Thu, 31 Oct 2019 08:51:47 -0700 (PDT) Date: Thu, 31 Oct 2019 15:51:45 +0000 From: Catalin Marinas To: Nicolas Saenz Julienne Cc: Qian Cai , f.fainelli@gmail.com, mbrugger@suse.com, marc.zyngier@arm.com, Linux Kernel Mailing List , linux-mm@kvack.org, Rob Herring , linux-rpi-kernel@lists.infradead.org, m.szyprowski@samsung.com, Robin Murphy , phill@raspberrypi.org, will@kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org, wahrenst@gmx.net Subject: Re: [PATCH v6 3/4] arm64: use both ZONE_DMA and ZONE_DMA32 Message-ID: <20191031155145.GF39590@arrakis.emea.arm.com> References: <6703f8dab4a21fe4e1049f8f224502e1733bf72c.camel@suse.de> <9208de061fe2b9ee7b74206b3cd52cc116e43ac0.camel@suse.de> <1956a2c8f4911b2a7e2ba3c53506c0f06efb93f8.camel@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1956a2c8f4911b2a7e2ba3c53506c0f06efb93f8.camel@suse.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: (sorry, I've been away last week and only now caught up with emails) On Tue, Oct 22, 2019 at 01:23:32PM +0200, Nicolas Saenz Julienne wrote: > On Mon, 2019-10-21 at 16:36 -0400, Qian Cai wrote: > > I managed to get more information here, > > > > [ 0.000000] cma: dma_contiguous_reserve(limit c0000000) > > [ 0.000000] cma: dma_contiguous_reserve: reserving 64 MiB for global area > > [ 0.000000] cma: cma_declare_contiguous(size 0x0000000004000000, base > > 0x0000000000000000, limit 0x00000000c0000000 alignment 0x0000000000000000) > > [ 0.000000] cma: Failed to reserve 512 MiB > > > > Full dmesg: > > > > https://cailca.github.io/files/dmesg.txt > > OK I got it, reproduced it too. > > Here are the relevant logs: > > [ 0.000000] DMA [mem 0x00000000802f0000-0x00000000bfffffff] > [ 0.000000] DMA32 [mem 0x00000000c0000000-0x00000000ffffffff] > [ 0.000000] Normal [mem 0x0000000100000000-0x00000097fcffffff] > > As you can see ZONE_DMA spans from 0x00000000802f0000-0x00000000bfffffff which > is slightly smaller than 1GB. > > [ 0.000000] crashkernel reserved: 0x000000009fe00000 - 0x00000000bfe00000 (512 MB) > > Here crashkernel reserved 512M in ZONE_DMA. > > [ 0.000000] cma: Failed to reserve 512 MiB > > CMA tried to allocate 512M in ZONE_DMA which fails as there is no enough space. > Makes sense. > > A fix could be moving crashkernel reservations after CMA and then if unable to > fit in ZONE_DMA try ZONE_DMA32 before bailing out. Maybe it's a little over the > top, yet although most devices will be fine with ZONE_DMA32, the RPi4 needs > crashkernel to be reserved in ZONE_DMA. Does RPi4 need CMA in ZONE_DMA? If not, I'd rather reserve the CMA from ZONE_DMA32. Even if you moved the crash kernel, someone else might complain that they had 2GB of CMA and it no longer works. -- Catalin