From: John Stultz <john.stultz@linaro.org> To: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Cc: Amit Pundir <amit.pundir@linaro.org>, Florian Fainelli <f.fainelli@gmail.com>, Will Deacon <will@kernel.org>, mbrugger@suse.com, Marc Zyngier <marc.zyngier@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, lkml <linux-kernel@vger.kernel.org>, Bjorn Andersson <bjorn.andersson@linaro.org>, linux-mm <linux-mm@kvack.org>, Rob Herring <robh+dt@kernel.org>, wahrenst@gmx.net, Nicolas Dechense <nicolas.dechesne@linaro.org>, Marek Szyprowski <m.szyprowski@samsung.com>, Robin Murphy <robin.murphy@arm.com>, Christoph Hellwig <hch@lst.de>, linux-arm-kernel <linux-arm-kernel@lists.infradead.org>, linux-rpi-kernel@lists.infradead.org Subject: Re: [PATCH v6 3/4] arm64: use both ZONE_DMA and ZONE_DMA32 Date: Mon, 2 Dec 2019 22:03:17 -0800 Message-ID: <CALAqxLW7RTif_NPxFXnxfTm2_ST+6aNmE6X=3v4XsuojKH2mtg@mail.gmail.com> (raw) In-Reply-To: <CALAqxLUkPNf9JYyt+_VOrxq=Zq03veb1y-7aDx+_Vw+fF9i82A@mail.gmail.com> On Mon, Dec 2, 2019 at 9:38 PM John Stultz <john.stultz@linaro.org> wrote: > On Mon, Dec 2, 2019 at 9:08 PM John Stultz <john.stultz@linaro.org> wrote: > > Hey Nicolas, > > Testing the db845c with linus/master, I found a regression causing > > system hangs in early boot: ... > > In the above log: > > [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: -188245 > > looks the most suspect, and going back to the working a573cdd7973d + > > build fix I see: > > [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 957419 > > > > Do you have any suggestions for what might be going wrong? > > Digging further, it seems the error is found in calculate_node_totalpages() > real_size = size - zone_absent_pages_in_node(pgdat->node_id, i, > node_start_pfn, node_end_pfn, > zholes_size); > > Where for zone DMA32 size is 262144, but real_size is calculated as -883520. > > I've not traced through to figure out why zone_absent_pages_in_node is > coming up with such a large number yet, but I'm about to crash so I > wanted to share. 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). thanks -john _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply index Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-09-11 18:25 [PATCH v6 0/4] Raspberry Pi 4 DMA addressing support Nicolas Saenz Julienne 2019-09-11 18:25 ` [PATCH v6 1/4] arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys() Nicolas Saenz Julienne 2019-09-11 18:25 ` [PATCH v6 2/4] arm64: rename variables used to calculate ZONE_DMA32's size Nicolas Saenz Julienne 2019-09-11 18:25 ` [PATCH v6 3/4] arm64: use both ZONE_DMA and ZONE_DMA32 Nicolas Saenz Julienne 2019-10-21 14:15 ` Qian Cai 2019-10-21 14:34 ` Nicolas Saenz Julienne 2019-10-21 14:46 ` Qian Cai 2019-10-21 17:01 ` Nicolas Saenz Julienne 2019-10-21 17:25 ` Qian Cai 2019-10-21 17:55 ` Nicolas Saenz Julienne 2019-10-21 20:36 ` Qian Cai 2019-10-22 11:23 ` Nicolas Saenz Julienne 2019-10-23 7:11 ` Matthias Brugger 2019-10-31 15:51 ` Catalin Marinas 2019-10-31 16:04 ` Nicolas Saenz Julienne 2019-10-31 18:02 ` Catalin Marinas 2019-10-31 18:11 ` Nicolas Saenz Julienne 2019-10-31 18:13 ` Catalin Marinas 2019-12-03 5:08 ` John Stultz 2019-12-03 5:38 ` John Stultz 2019-12-03 6:03 ` John Stultz [this message] 2019-12-03 10:12 ` Will Deacon 2019-12-03 11:19 ` Catalin Marinas 2019-09-11 18:25 ` [PATCH v6 4/4] mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type' Nicolas Saenz Julienne 2019-10-01 16:05 ` [PATCH v6 0/4] Raspberry Pi 4 DMA addressing support Catalin Marinas
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to='CALAqxLW7RTif_NPxFXnxfTm2_ST+6aNmE6X=3v4XsuojKH2mtg@mail.gmail.com' \ --to=john.stultz@linaro.org \ --cc=amit.pundir@linaro.org \ --cc=bjorn.andersson@linaro.org \ --cc=catalin.marinas@arm.com \ --cc=f.fainelli@gmail.com \ --cc=hch@lst.de \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux-rpi-kernel@lists.infradead.org \ --cc=m.szyprowski@samsung.com \ --cc=marc.zyngier@arm.com \ --cc=mbrugger@suse.com \ --cc=nicolas.dechesne@linaro.org \ --cc=nsaenzjulienne@suse.de \ --cc=robh+dt@kernel.org \ --cc=robin.murphy@arm.com \ --cc=wahrenst@gmx.net \ --cc=will@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Linux-ARM-Kernel Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \ linux-arm-kernel@lists.infradead.org public-inbox-index linux-arm-kernel Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel AGPL code for this site: git clone https://public-inbox.org/public-inbox.git