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[209.132.180.67]) by mx.google.com with ESMTP id u15si284837oic.269.2020.03.10.18.45.44; Tue, 10 Mar 2020 18:45:56 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727900AbgCKBoh (ORCPT + 99 others); Tue, 10 Mar 2020 21:44:37 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:11221 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727484AbgCKBoh (ORCPT ); Tue, 10 Mar 2020 21:44:37 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id E369A6DBBBE6CDEAE369; Wed, 11 Mar 2020 09:44:24 +0800 (CST) Received: from [127.0.0.1] (10.173.223.253) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.487.0; Wed, 11 Mar 2020 09:44:17 +0800 Subject: Re: [PATCH v7 2/4] arm64: kdump: reserve crashkenel above 4G for crash dump kernel To: Prabhakar Kushwaha References: <20191223152349.180172-1-chenzhou10@huawei.com> <20191223152349.180172-3-chenzhou10@huawei.com> <0c00f14a-15ca-44db-7f82-00f15ddd3c88@huawei.com> <3bfc5799-1fc4-d5e3-cf32-24ed9fb02b1b@gmail.com> CC: Thomas Gleixner , , Catalin Marinas , Will Deacon , James Morse , , Bhupesh Sharma , , Linux Doc Mailing List , kexec mailing list , Linux Kernel Mailing List , , linux-arm-kernel , Ganapatrao Prabhakerrao Kulkarni From: chenzhou Message-ID: <93218141-e88a-23db-45ff-4075f3833b3a@huawei.com> Date: Wed, 11 Mar 2020 09:44:16 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <3bfc5799-1fc4-d5e3-cf32-24ed9fb02b1b@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.173.223.253] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/3/11 1:08, Prabhakar Kushwaha wrote: > On 3/10/2020 7:00 AM, chenzhou wrote: >> Hi, >> >> On 2020/3/9 23:51, Prabhakar Kushwaha wrote: >>> On 3/9/2020 10:18 AM, Prabhakar Kushwaha wrote: >>>> Hi Chen, >>>> >>>> On Sat, Mar 7, 2020 at 4:36 PM Chen Zhou wrote: >>>>> >>>>> >>>>> >>>>> On 2020/3/5 18:13, Prabhakar Kushwaha wrote: >>>>>> On Mon, Dec 23, 2019 at 8:57 PM Chen Zhou wrote: >>>>>>> >>>>>>> Crashkernel=X tries to reserve memory for the crash dump kernel under >>>>>>> 4G. If crashkernel=X,low is specified simultaneously, reserve spcified >>>>>>> size low memory for crash kdump kernel devices firstly and then reserve >>>>>>> memory above 4G. >>>>>>> >>>>>>> Signed-off-by: Chen Zhou >>>>>>> --- >>>>>>> arch/arm64/kernel/setup.c | 8 +++++++- >>>>>>> arch/arm64/mm/init.c | 31 +++++++++++++++++++++++++++++-- >>>>>>> 2 files changed, 36 insertions(+), 3 deletions(-) >>>>>>> >>>>>>> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c >>>>>>> index 56f6645..04d1c87 100644 >>>>>>> --- a/arch/arm64/kernel/setup.c >>>>>>> +++ b/arch/arm64/kernel/setup.c >>>>>>> @@ -238,7 +238,13 @@ static void __init request_standard_resources(void) >>>>>>> kernel_data.end <= res->end) >>>>>>> request_resource(res, &kernel_data); >>>>>>> #ifdef CONFIG_KEXEC_CORE >>>>>>> - /* Userspace will find "Crash kernel" region in /proc/iomem. */ >>>>>>> + /* >>>>>>> + * Userspace will find "Crash kernel" region in /proc/iomem. >>>>>>> + * Note: the low region is renamed as Crash kernel (low). >>>>>>> + */ >>>>>>> + if (crashk_low_res.end && crashk_low_res.start >= res->start && >>>>>>> + crashk_low_res.end <= res->end) >>>>>>> + request_resource(res, &crashk_low_res); >>>>>>> if (crashk_res.end && crashk_res.start >= res->start && >>>>>>> crashk_res.end <= res->end) >>>>>>> request_resource(res, &crashk_res); >>>>>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >>>>>>> index b65dffd..0d7afd5 100644 >>>>>>> --- a/arch/arm64/mm/init.c >>>>>>> +++ b/arch/arm64/mm/init.c >>>>>>> @@ -80,6 +80,7 @@ static void __init reserve_crashkernel(void) >>>>>>> { >>>>>>> unsigned long long crash_base, crash_size; >>>>>>> int ret; >>>>>>> + phys_addr_t crash_max = arm64_dma32_phys_limit; >>>>>>> >>>>>>> ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), >>>>>>> &crash_size, &crash_base); >>>>>>> @@ -87,12 +88,38 @@ static void __init reserve_crashkernel(void) >>>>>>> if (ret || !crash_size) >>>>>>> return; >>>>>>> >>>>>>> + ret = reserve_crashkernel_low(); >>>>>>> + if (!ret && crashk_low_res.end) { >>>>>>> + /* >>>>>>> + * If crashkernel=X,low specified, there may be two regions, >>>>>>> + * we need to make some changes as follows: >>>>>>> + * >>>>>>> + * 1. rename the low region as "Crash kernel (low)" >>>>>>> + * In order to distinct from the high region and make no effect >>>>>>> + * to the use of existing kexec-tools, rename the low region as >>>>>>> + * "Crash kernel (low)". >>>>>>> + * >>>>>>> + * 2. change the upper bound for crash memory >>>>>>> + * Set MEMBLOCK_ALLOC_ACCESSIBLE upper bound for crash memory. >>>>>>> + * >>>>>>> + * 3. mark the low region as "nomap" >>>>>>> + * The low region is intended to be used for crash dump kernel >>>>>>> + * devices, just mark the low region as "nomap" simply. >>>>>>> + */ >>>>>>> + const char *rename = "Crash kernel (low)"; >>>>>>> + >>>>>>> + crashk_low_res.name = rename; >>>>>>> + crash_max = MEMBLOCK_ALLOC_ACCESSIBLE; >>>>>>> + memblock_mark_nomap(crashk_low_res.start, >>>>>>> + resource_size(&crashk_low_res)); >>>>>>> + } >>>>>>> + >>>>>>> crash_size = PAGE_ALIGN(crash_size); >>>>>>> >>>>>>> if (crash_base == 0) { >>>>>>> /* Current arm64 boot protocol requires 2MB alignment */ >>>>>>> - crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, >>>>>>> - crash_size, SZ_2M); >>>>>>> + crash_base = memblock_find_in_range(0, crash_max, crash_size, >>>>>>> + SZ_2M); >>>>>>> if (crash_base == 0) { >>>>>>> pr_warn("cannot allocate crashkernel (size:0x%llx)\n", >>>>>>> crash_size); >>>>>>> -- >>>>>> >>>>>> I tested this patch series on ARM64-ThunderX2 with no issue with >>>>>> bootargs crashkenel=X@Y crashkernel=250M,low >>>>>> >>>>>> $ dmesg | grep crash >>>>>> [ 0.000000] crashkernel reserved: 0x0000000b81200000 - >>>>>> 0x0000000c81200000 (4096 MB) >>>>>> [ 0.000000] Kernel command line: >>>>>> BOOT_IMAGE=/boot/vmlinuz-5.6.0-rc4+ >>>>>> root=UUID=866b8df3-14f4-4e11-95a1-74a90ee9b694 ro >>>>>> crashkernel=4G@0xb81200000 crashkernel=250M,low nowatchdog earlycon >>>>>> [ 29.310209] crashkernel=250M,low >>>>>> >>>>>> $ kexec -p -i /boot/vmlinuz-`uname -r` >>>>>> --initrd=/boot/initrd.img-`uname -r` --reuse-cmdline >>>>>> $ echo 1 > /proc/sys/kernel/sysrq ; echo c > /proc/sysrq-trigger >>>>>> >>>>>> But when i tried with crashkernel=4G crashkernel=250M,low as bootargs. >>>>>> Kernel is not able to allocate memory. >>>>>> [ 0.000000] cannot allocate crashkernel (size:0x100000000) >>>>>> [ 0.000000] Kernel command line: >>>>>> BOOT_IMAGE=/boot/vmlinuz-5.6.0-rc4+ >>>>>> root=UUID=866b8df3-14f4-4e11-95a1-74a90ee9b694 ro crashkernel=4G >>>>>> crashkernel=250M,low nowatchdog >>>>>> [ 29.332081] crashkernel=250M,low >>>>>> >>>>>> does crashkernel=X@Y mandatory to get allocated beyond 4G? >>>>>> am I missing something? >>>>> >>>>> I can't reproduce the problem in my environment, can you test with other size, >>>>> such as "crashkernel=1G crashkernel=250M,low", see if there is the same issue. >>>>> >>>> I tried 1G also. Same error, please find the logs >>>> >>>> $ dmesg | grep crash >>>> [ 0.000000] cannot allocate crashkernel (size:0x40000000) >>>> [ 0.000000] Kernel command line: >>>> BOOT_IMAGE=/boot/vmlinuz-5.6.0-rc4+ >>>> root=UUID=866b8df3-14f4-4e11-95a1-74a90ee9b694 ro nowatchdog earlycon >>>> crashkernel=1G crashkernel=250M,low >>>> [ 29.326916] crashkernel=250M,low >>>> >>>> >>>>> Besides, crashkernel=X@Y isn't mandatory to get allocated beyond 4G, >>>> >>>> this was my understanding also. >>>> >>>>> can you show the whole file /proc/iomem. >>>>> >>>> >>>> $ cat /proc/iomem >>>> 00000000-00000000 : PCI ECAM >>>> 00000000-00000000 : PCI ECAM >>>> 00000000-00000000 : PCI Bus 0000:00 >>>> 00000000-00000000 : PCI Bus 0000:0f >>>> 00000000-00000000 : PCI Bus 0000:10 >>>> 00000000-00000000 : 0000:10:00.0 >>>> 00000000-00000000 : 0000:10:00.0 >>>> 00000000-00000000 : PCI Bus 0000:01 >>>> 00000000-00000000 : 0000:01:00.0 >>>> 00000000-00000000 : 0000:01:00.1 >>>> 00000000-00000000 : PCI Bus 0000:05 >>>> 00000000-00000000 : 0000:05:00.0 >>>> 00000000-00000000 : 0000:05:00.1 >>>> 00000000-00000000 : PCI Bus 0000:09 >>>> 00000000-00000000 : 0000:09:00.0 >>>> 00000000-00000000 : 0000:09:00.1 >>>> 00000000-00000000 : 0000:00:10.0 >>>> 00000000-00000000 : ahci >>>> 00000000-00000000 : 0000:00:10.1 >>>> 00000000-00000000 : ahci >>>> 00000000-00000000 : PCI Bus 0000:80 >>>> 00000000-00000000 : PCI Bus 0000:83 >>>> 00000000-00000000 : 0000:83:00.0 >>>> 00000000-00000000 : 0000:83:00.0 >>>> 00000000-00000000 : nvme >>>> 00000000-00000000 : PCI Bus 0000:89 >>>> 00000000-00000000 : 0000:89:00.0 >>>> 00000000-00000000 : e1000e >>>> 00000000-00000000 : 0000:89:00.0 >>>> 00000000-00000000 : 0000:89:00.0 >>>> 00000000-00000000 : e1000e >>>> 00000000-00000000 : 0000:89:00.0 >>>> 00000000-00000000 : e1000e >>>> 00000000-00000000 : PCI Bus 0000:8d >>>> 00000000-00000000 : 0000:8d:00.0 >>>> 00000000-00000000 : 0000:8d:00.0 >>>> 00000000-00000000 : mpt3sas >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : Kernel code >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : Kernel data >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : CAV901C:00 >>>> 00000000-00000000 : CAV901D:00 >>>> 00000000-00000000 : CAV901C:00 >>>> 00000000-00000000 : CAV901E:00 >>>> 00000000-00000000 : CAV901C:00 >>>> 00000000-00000000 : CAV901F:00 >>>> 00000000-00000000 : CAV901C:00 >>>> 00000000-00000000 : CAV9006:00 >>>> 00000000-00000000 : CAV9006:00 >>>> 00000000-00000000 : ARMH0011:00 >>>> 00000000-00000000 : ARMH0011:00 >>>> 00000000-00000000 : arm-smmu-v3.0.auto >>>> 00000000-00000000 : arm-smmu-v3.0.auto >>>> 00000000-00000000 : arm-smmu-v3.1.auto >>>> 00000000-00000000 : arm-smmu-v3.1.auto >>>> 00000000-00000000 : arm-smmu-v3.2.auto >>>> 00000000-00000000 : arm-smmu-v3.2.auto >>>> 00000000-00000000 : CAV901C:01 >>>> 00000000-00000000 : CAV901D:01 >>>> 00000000-00000000 : CAV901C:01 >>>> 00000000-00000000 : CAV901E:01 >>>> 00000000-00000000 : CAV901C:01 >>>> 00000000-00000000 : CAV901F:01 >>>> 00000000-00000000 : CAV901C:01 >>>> 00000000-00000000 : CAV9007:06 >>>> 00000000-00000000 : CAV9007:06 >>>> 00000000-00000000 : arm-smmu-v3.3.auto >>>> 00000000-00000000 : arm-smmu-v3.3.auto >>>> 00000000-00000000 : arm-smmu-v3.4.auto >>>> 00000000-00000000 : arm-smmu-v3.4.auto >>>> 00000000-00000000 : arm-smmu-v3.5.auto >>>> 00000000-00000000 : arm-smmu-v3.5.auto >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : System RAM >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : reserved >>>> 00000000-00000000 : PCI Bus 0000:00 >>>> 00000000-00000000 : PCI Bus 0000:01 >>>> 00000000-00000000 : 0000:01:00.0 >>>> 00000000-00000000 : 0000:01:00.1 >>>> 00000000-00000000 : 0000:01:00.0 >>>> 00000000-00000000 : 0000:01:00.1 >>>> 00000000-00000000 : 0000:01:00.0 >>>> 00000000-00000000 : 0000:01:00.1 >>>> 00000000-00000000 : PCI Bus 0000:05 >>>> 00000000-00000000 : 0000:05:00.0 >>>> 00000000-00000000 : bnx2x >>>> 00000000-00000000 : 0000:05:00.1 >>>> 00000000-00000000 : bnx2x >>>> 00000000-00000000 : 0000:05:00.0 >>>> 00000000-00000000 : bnx2x >>>> 00000000-00000000 : 0000:05:00.0 >>>> 00000000-00000000 : bnx2x >>>> 00000000-00000000 : 0000:05:00.1 >>>> 00000000-00000000 : bnx2x >>>> 00000000-00000000 : 0000:05:00.1 >>>> 00000000-00000000 : bnx2x >>>> 00000000-00000000 : PCI Bus 0000:09 >>>> 00000000-00000000 : 0000:09:00.0 >>>> 00000000-00000000 : i40e >>>> 00000000-00000000 : 0000:09:00.1 >>>> 00000000-00000000 : i40e >>>> 00000000-00000000 : 0000:09:00.0 >>>> 00000000-00000000 : 0000:09:00.1 >>>> 00000000-00000000 : 0000:09:00.0 >>>> 00000000-00000000 : i40e >>>> 00000000-00000000 : 0000:09:00.1 >>>> 00000000-00000000 : i40e >>>> 00000000-00000000 : 0000:09:00.0 >>>> 00000000-00000000 : 0000:09:00.1 >>>> 00000000-00000000 : 0000:00:0f.0 >>>> 00000000-00000000 : xhci-hcd >>>> 00000000-00000000 : 0000:00:0f.0 >>>> 00000000-00000000 : 0000:00:0f.1 >>>> 00000000-00000000 : xhci-hcd >>>> 00000000-00000000 : 0000:00:0f.1 >>>> 00000000-00000000 : 0000:00:10.0 >>>> 00000000-00000000 : ahci >>>> 00000000-00000000 : 0000:00:10.1 >>>> 00000000-00000000 : ahci >>>> 00000000-00000000 : PCI Bus 0000:80 >>>> >>> >>> resending with correct logs (after login as root) >>> >>> $ cat /proc/iomem >>> 30000000-37ffffff : PCI ECAM >>> 38000000-3fffffff : PCI ECAM >>> 40000000-5fffffff : PCI Bus 0000:00 >>> 40000000-417fffff : PCI Bus 0000:0f >>> 40000000-417fffff : PCI Bus 0000:10 >>> 40000000-40ffffff : 0000:10:00.0 >>> 41000000-4101ffff : 0000:10:00.0 >>> 41800000-418fffff : PCI Bus 0000:01 >>> 41800000-4183ffff : 0000:01:00.0 >>> 41840000-4187ffff : 0000:01:00.1 >>> 41900000-419fffff : PCI Bus 0000:05 >>> 41900000-4197ffff : 0000:05:00.0 >>> 41980000-419fffff : 0000:05:00.1 >>> 41a00000-41afffff : PCI Bus 0000:09 >>> 41a00000-41a7ffff : 0000:09:00.0 >>> 41a80000-41afffff : 0000:09:00.1 >>> 41b00000-41b0ffff : 0000:00:10.0 >>> 41b00000-41b0ffff : ahci >>> 41b10000-41b1ffff : 0000:00:10.1 >>> 41b10000-41b1ffff : ahci >>> 60000000-7fffffff : PCI Bus 0000:80 >>> 60000000-600fffff : PCI Bus 0000:83 >>> 60000000-6001ffff : 0000:83:00.0 >>> 60020000-60023fff : 0000:83:00.0 >>> 60020000-60023fff : nvme >>> 60100000-601fffff : PCI Bus 0000:89 >>> 60100000-6017ffff : 0000:89:00.0 >>> 60100000-6017ffff : e1000e >>> 60180000-601bffff : 0000:89:00.0 >>> 601c0000-601dffff : 0000:89:00.0 >>> 601c0000-601dffff : e1000e >>> 601e0000-601e3fff : 0000:89:00.0 >>> 601e0000-601e3fff : e1000e >>> 60200000-603fffff : PCI Bus 0000:8d >>> 60200000-602fffff : 0000:8d:00.0 >>> 60300000-6030ffff : 0000:8d:00.0 >>> 60300000-6030ffff : mpt3sas >>> 802f0000-8030ffff : reserved >>> e6247000-e6247fff : reserved >>> e6720000-e690ffff : reserved >>> e6a90000-e6a9ffff : reserved >>> e6ab0000-e721ffff : reserved >>> e7240000-e7240fff : reserved >>> fac00000-fafdffff : reserved >>> 400040400-40004041f : CAV901C:00 >>> 400040480-400040567 : CAV901D:00 >>> 400040480-400040567 : CAV901C:00 >>> 400040600-40004073b : CAV901E:00 >>> 400040600-40004073b : CAV901C:00 >>> 400041400-40004177f : CAV901F:00 >>> 400041400-40004177f : CAV901C:00 >>> 402000100-402000fff : CAV9006:00 >>> 402000100-402000fff : CAV9006:00 >>> 402020000-40202ffff : ARMH0011:00 >>> 402020000-40202ffff : ARMH0011:00 >>> 402300000-40230ffff : arm-smmu-v3.0.auto >>> 402300000-40230ffff : arm-smmu-v3.0.auto >>> 402320000-40232ffff : arm-smmu-v3.1.auto >>> 402320000-40232ffff : arm-smmu-v3.1.auto >>> 402340000-40234ffff : arm-smmu-v3.2.auto >>> 402340000-40234ffff : arm-smmu-v3.2.auto >>> 440040400-44004041f : CAV901C:01 >>> 440040480-440040567 : CAV901D:01 >>> 440040480-440040567 : CAV901C:01 >>> 440040600-44004073b : CAV901E:01 >>> 440040600-44004073b : CAV901C:01 >>> 440041400-44004177f : CAV901F:01 >>> 440041400-44004177f : CAV901C:01 >>> 4421a0000-4421affff : CAV9007:06 >>> 4421a0000-4421affff : CAV9007:06 >>> 442300000-44230ffff : arm-smmu-v3.3.auto >>> 442300000-44230ffff : arm-smmu-v3.3.auto >>> 442320000-44232ffff : arm-smmu-v3.4.auto >>> 442320000-44232ffff : arm-smmu-v3.4.auto >>> 442340000-44234ffff : arm-smmu-v3.5.auto >>> 442340000-44234ffff : arm-smmu-v3.5.auto >>> b81200000-c811fffff : System RAM >>> b81280000-b8270ffff : Kernel code >>> b82710000-b82dfffff : reserved >>> b82e00000-b83168fff : Kernel data >>> b83169000-baccd7fff : reserved >>> c78a00000-c7fffffff : reserved >>> c80129000-c801a9fff : reserved >>> c801aa000-c809e9fff : reserved >>> c809ec000-c809eefff : reserved >>> c809ef000-c811fffff : reserved >>> 10000000000-13fffffffff : PCI Bus 0000:00 >>> 10000000000-100013fffff : PCI Bus 0000:01 >>> 10000000000-100007fffff : 0000:01:00.0 >>> 10000800000-10000ffffff : 0000:01:00.1 >>> 10001000000-1000101ffff : 0000:01:00.0 >>> 10001020000-1000103ffff : 0000:01:00.1 >>> 10001040000-1000104ffff : 0000:01:00.0 >>> 10001050000-1000105ffff : 0000:01:00.1 >>> 10001400000-100037fffff : PCI Bus 0000:05 >>> 10001400000-1000140ffff : 0000:05:00.0 >>> 10001400000-1000140ffff : bnx2x >>> 10001410000-1000141ffff : 0000:05:00.1 >>> 10001410000-1000141ffff : bnx2x >>> 10001800000-10001ffffff : 0000:05:00.0 >>> 10001800000-10001ffffff : bnx2x >>> 10002000000-100027fffff : 0000:05:00.0 >>> 10002000000-100027fffff : bnx2x >>> 10002800000-10002ffffff : 0000:05:00.1 >>> 10002800000-10002ffffff : bnx2x >>> 10003000000-100037fffff : 0000:05:00.1 >>> 10003000000-100037fffff : bnx2x >>> 10003800000-100053fffff : PCI Bus 0000:09 >>> 10003800000-10003ffffff : 0000:09:00.0 >>> 10003800000-10003ffffff : i40e >>> 10004000000-100047fffff : 0000:09:00.1 >>> 10004000000-100047fffff : i40e >>> 10004800000-10004bfffff : 0000:09:00.0 >>> 10004c00000-10004ffffff : 0000:09:00.1 >>> 10005000000-10005007fff : 0000:09:00.0 >>> 10005000000-10005007fff : i40e >>> 10005008000-1000500ffff : 0000:09:00.1 >>> 10005008000-1000500ffff : i40e >>> 10005010000-1000510ffff : 0000:09:00.0 >>> 10005110000-1000520ffff : 0000:09:00.1 >>> 10005400000-1000540ffff : 0000:00:0f.0 >>> 10005400000-1000540ffff : xhci-hcd >>> 10005410000-1000541ffff : 0000:00:0f.0 >>> 10005420000-1000542ffff : 0000:00:0f.1 >>> 10005420000-1000542ffff : xhci-hcd >>> 10005430000-1000543ffff : 0000:00:0f.1 >>> 10005440000-1000544ffff : 0000:00:10.0 >>> 10005440000-1000544ffff : ahci >>> 10005450000-1000545ffff : 0000:00:10.1 >>> 10005450000-1000545ffff : ahci >>> 14000000000-17fffffffff : PCI Bus 0000:80 >>> >>> >>> failure with crashkernel=1G >>> >>> :~$ dmesg | grep crash >>> [ 0.000000] cannot allocate crashkernel (size:0x40000000) >>> [ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.6.0-rc4+ >>> root=UUID=866b8df3-14f4-4e11-95a1-74a90ee9b694 ro nowatchdog earlycon >>> crashkernel=1G crashkernel=250M,low >>> [ 29.326916] crashkernel=250M,low >>> >> >> I read these clearly, found that your all testcases failed including >> "crashkernel=4G@0xb81200000 crashkernel=250M,low". >> > > I tested 3 scenarios > 1) crashkernel=4G@0xb81200000 crashkernel=250M,low : Allocation Passed > 2) crashkernel=4G crashkernel=250M,low : Allocation failed > 3) crashkernel=2G crashkernel=250M,low : Allocation failed > 4) crashkernel=1G crashkernel=250M,low : Allocation failed > > >> There is no "Crash kernel (low)" in all your tests, that is there is no enough >> low memory, in these cases, parameters equal to 4G@0xb81200000, crashkernel=4G >> and crashkernel=1G. >> >> crashkernel=4G and crashkernel=1G all failed because there is no low memory. >> > > > As per my understanding, this patch series allow to allocate memory > above 4G range. So For crashkernel = 1G: if no memory found in low > memory range, it will automatically be allocated from above 4G range. > Yeah, you are right. We also discussed about this, and i did like this in my v5(https://lkml.org/lkml/2019/5/6/1361). Current version is simplified. Thanks, Chen Zhou > > --pk > > > . >