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 <chenzhou10@xxxxxxxxxx> wrote: >>>> >>>> >>>> >>>> On 2020/3/5 18:13, Prabhakar Kushwaha wrote: >>>>> On Mon, Dec 23, 2019 at 8:57 PM Chen Zhou <chenzhou10@xxxxxxxxxx> 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@xxxxxxxxxx> >>>>>> --- >>>>>> 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. --pk _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec