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Mon, 5 Oct 2020 13:42:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601919744; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lTv8qVn50BVMe41mnHOhz5zFgfNAnMlsJzHtN4tUUYY=; b=bcrPOG5WzxlRbADGHmq3n7/I3sPoquZde/Zzy49TBoknUVzSSwVcLbuodKJKGU4IcairOE gRdMjICMonAVMPzeCQZcV09KiDueo64vaDvvFuMbC2WN+/y6JciB8q88q1yZK3IE7qzuDR EyLdN1K0VHn8PWvbul42RZ1ng8QG8tU= Received: from mail-oi1-f200.google.com (mail-oi1-f200.google.com [209.85.167.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-104-9bxhHGEaPuOkDzEb8xMGlA-1; Mon, 05 Oct 2020 13:42:23 -0400 X-MC-Unique: 9bxhHGEaPuOkDzEb8xMGlA-1 Received: by mail-oi1-f200.google.com with SMTP id z25so2000517oih.23 for ; Mon, 05 Oct 2020 10:42:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lTv8qVn50BVMe41mnHOhz5zFgfNAnMlsJzHtN4tUUYY=; b=ukn8QdsLuSpkwyInDvsmqYQ49tQEAG8U8BGhcyX6TEZloQPZ4WRXWtyOXcBojELE1Y Qp6gsdaSgFK73ZjrzvW2mm/BpWd+WpZZ5EDfVr88l1/StqKLBC1OGkhdEOT/eOUi77Pi ypfp1MIef6y8+CMGT22oJaO3a3wKken5p34XzbwF/919pavMXBGmjIbYaYFGN9dXgp/j CzQ/yUbo6btvDNrVpHNTB3n9Qj6Z2QSLkozvHs3oPUSerIVhKuSEeX3TA5RJEESNjfbX 8TU8hpr2m7Y8TCZ+YDA/ucD/S7MSWTxez5ODEUitaWq+sDssqhVLoHyLZFU6A3NW559R GrKQ== X-Gm-Message-State: AOAM533g1IkSgz5dNIkCF2w52a5YoJlwgIVQfmW8seLVhmEH5EqpHstO dVtJKtNZuXDv86UrIyWdaSwcNXc+uvs7DozEiXWnNIO/s0Lvz+vRMkdGdjXwIBkh3jwpAGsWCXZ UNQT7YR01KAt2PlP9heET1nVRv1gdJ/fCzIW2JjvK X-Received: by 2002:a9d:a24:: with SMTP id 33mr255765otg.305.1601919741907; Mon, 05 Oct 2020 10:42:21 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyUwdJyVHIEtrpCyi9x3L1lyrhCd75vZ9+/aBnXjciOlpkIe+CX5Y4ESH+Vq6Rhy3CxhWne8HCSfmc8OJPjzQc= X-Received: by 2002:a9d:a24:: with SMTP id 33mr255732otg.305.1601919741596; Mon, 05 Oct 2020 10:42:21 -0700 (PDT) MIME-Version: 1.0 References: <20200907134745.25732-1-chenzhou10@huawei.com> <20201005170937.GA14576@gaia> In-Reply-To: <20201005170937.GA14576@gaia> From: Bhupesh Sharma Date: Mon, 5 Oct 2020 23:12:10 +0530 Message-ID: Subject: Re: [PATCH v12 0/9] support reserving crashkernel above 4G on arm64 kdump To: Catalin Marinas Cc: John Donnelly , Chen Zhou , Will Deacon , James Morse , Thomas Gleixner , Ingo Molnar , RuiRui Yang , Baoquan He , Jonathan Corbet , Prabhakar Kushwaha , Simon Horman , Rob Herring , Arnd Bergmann , nsaenzjulienne@suse.de, linux-arm-kernel , Linux Kernel Mailing List , kexec mailing list , Linux Doc Mailing List , guohanjun@huawei.com, xiexiuqi@huawei.com, huawei.libin@huawei.com, wangkefeng.wang@huawei.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Catalin, Chen, On Mon, Oct 5, 2020 at 10:39 PM Catalin Marinas wrote: > > On Sat, Sep 12, 2020 at 06:44:29AM -0500, John Donnelly wrote: > > On 9/7/20 8:47 AM, Chen Zhou wrote: > > > Chen Zhou (9): > > > x86: kdump: move CRASH_ALIGN to 2M > > > x86: kdump: make the lower bound of crash kernel reservation > > > consistent > > > x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions > > > reserve_crashkernel[_low]() > > > x86: kdump: move reserve_crashkernel[_low]() into crash_core.c > > > arm64: kdump: introduce some macroes for crash kernel reservation > > > arm64: kdump: reimplement crashkernel=X > > > kdump: add threshold for the required memory > > > arm64: kdump: add memory for devices by DT property > > > linux,usable-memory-range > > > kdump: update Documentation about crashkernel > [...] > > I did a brief unit-test on 5.9-rc4. > > > > Please add: > > > > Tested-by: John Donnelly > > Thanks for testing. > > > This activity is over a year old. It needs accepted. > > It's getting there, hopefully in 5.11. There are some minor tweaks to > address. I think my earlier email with the test results on this series bounced off the mailing list server (for some weird reason), but I still see several issues with this patchset. I will add specific issues in the review comments for each patch again, but overall, with a crashkernel size of say 786M, I see the following issue: # cat /proc/cmdline BOOT_IMAGE=(hd7,gpt2)/vmlinuz-5.9.0-rc7+ root=<..snip..> rd.lvm.lv=<..snip..> crashkernel=786M I see two regions of size 786M and 256M reserved in low and high regions respectively, So we reserve a total of 1042M of memory, which is an incorrect behaviour: # dmesg | grep -i crash [ 0.000000] Reserving 256MB of low memory at 2816MB for crashkernel (System low RAM: 768MB) [ 0.000000] Reserving 786MB of memory at 654158MB for crashkernel (System RAM: 130816MB) [ 0.000000] Kernel command line: BOOT_IMAGE=(hd2,gpt2)/vmlinuz-5.9.0-rc7+ root=/dev/mapper/rhel_ampere--hr330a--03-root ro rd.lvm.lv=rhel_ampere-hr330a-03/root rd.lvm.lv=rhel_ampere-hr330a-03/swap crashkernel=786M cma=1024M # cat /proc/iomem | grep -i crash b0000000-bfffffff : Crash kernel (low) bfcbe00000-bffcffffff : Crash kernel IMO, we should test this feature more before including this in 5.11 Thanks, Bhupesh