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SubjectRe: [PATCH v7 2/4] arm64: kdump: reserve crashkenel above 4G for crash dump kernel
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Date
On 3/9/2020 10:18 AM, Prabhakar Kushwaha wrote:
> Hi Chen,
>
> On Sat, Mar 7, 2020 at 4:36 PM Chen Zhou <chenzhou10@huawei.com> wrote:
>>
>>
>>
>> On 2020/3/5 18:13, Prabhakar Kushwaha wrote:
>>> On Mon, Dec 23, 2019 at 8:57 PM Chen Zhou <chenzhou10@huawei.com> 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 <chenzhou10@huawei.com>
>>>> ---
>>>> 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

--pk

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