Hi, On 21/07/16 01:57, AKASHI Takahiro wrote: > Could you please apply the diff attached below and confirm that > kdump works in your environment? > I can't test it by myself since my hikey board seems to be broken now. With this I get a failure even earlier, even with 'acpi=off'. With this patch, on boot of the kdump kernel I get: [ 0.000000] Linux version 4.7.0-rc4+ (morse at melchizedek) (gcc version 5.2.1 6 [ 0.000000] Boot CPU: AArch64 Processor [411fd071] [ 0.000000] earlycon: pl11 at MMIO 0x000000007ff80000 (options '') [ 0.000000] bootconsole [pl11] enabled [ 0.000000] debug: ignoring loglevel setting. [ 0.000000] efi: Getting EFI parameters from FDT: [ 0.000000] efi: EFI v2.50 by ARM Juno EFI Nov 24 2015 12:36:35 [ 0.000000] efi: ACPI=0xf95b0000 ACPI 2.0=0xf95b0014 PROP=0xfe8db4d8 [ 0.000000] Reserving 1KB of memory at 0x9fffff000 for elfcorehdr [ 0.000000] cma: Failed to reserve 16 MiB [ 0.000000] On node 0 totalpages: 132160 [ 0.000000] DMA zone: 17 pages used for memmap [ 0.000000] DMA zone: 0 pages reserved [ 0.000000] DMA zone: 1088 pages, LIFO batch:0 [ 0.000000] Normal zone: 2048 pages used for memmap [ 0.000000] Normal zone: 131072 pages, LIFO batch:31 [ 0.000000] bootmem alloc of 64 bytes failed! [ 0.000000] Kernel panic - not syncing: Out of memory [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.7.0-rc4+ #4600 [ 0.000000] Hardware name: ARM Juno development board (r1) (DT) [ 0.000000] Call trace: [ 0.000000] [<ffff0000080889a8>] dump_backtrace+0x0/0x1e8 [ 0.000000] [<ffff000008088ba4>] show_stack+0x14/0x20 [ 0.000000] [<ffff000008363274>] dump_stack+0x94/0xb8 [ 0.000000] [<ffff00000816192c>] panic+0x10c/0x278 [ 0.000000] [<ffff000008b14980>] free_bootmem_late+0x0/0xa0 [ 0.000000] [<ffff000008b14e68>] __alloc_bootmem_low+0x2c/0x38 [ 0.000000] [<ffff000008b02954>] setup_arch+0x2e4/0x5ac [ 0.000000] [<ffff000008b00854>] start_kernel+0x70/0x390 [ 0.000000] [<ffff000008b001bc>] __primary_switched+0x30/0x6c [ 0.000000] ---[ end Kernel panic - not syncing: Out of memory Trying again, booted with: > console=ttyAMA0,115200 earlycon=pl011,0x7ff80000 root=/dev/nfs > nfsroot=10.X.X.X:/ubuntu-15.04-server-arm64,v3 resume=/dev/sda2 no_console_suspend > ip=dhcp rw crashkernel=512M stacktrace ignore_loglevel=1 acpi=off efi=debug memblock=debug kexec-tools invoked as: > kexec -x --reuse-cmdline --dtb=/sys/firmware/fdt -p /aarch64-Image cat /proc/iomem | grep Crash: > 9e0000000-9ffffffff : Crash kernel crash kernel memblock before call to memblock_cap_memory_range(): [ 0.000000] MEMBLOCK configuration: [ 0.000000] memory size = 0x1fef10000 reserved size = 0x4f3b [ 0.000000] memory.cnt = 0x9 [ 0.000000] memory[0x0] [0x00000080000000-0x000000dfffffff], 0x60000000 bytes flags: 0x0 [ 0.000000] memory[0x1] [0x000000e00f0000-0x000000f949ffff], 0x193b0000 bytes flags: 0x0 (uefi runtime code|data|acpi:) [ 0.000000] memory[0x2] [0x000000f94a0000-0x000000f984ffff], 0x3b0000 bytes flags: 0x4 [ 0.000000] memory[0x3] [0x000000f9850000-0x000000fe81ffff], 0x4fd0000 bytes flags: 0x0 (uefi runtime data:) [ 0.000000] memory[0x4] [0x000000fe820000-0x000000fe85ffff], 0x40000 bytes flags: 0x4 [ 0.000000] memory[0x5] [0x000000fe860000-0x000000fe86ffff], 0x10000 bytes flags: 0x0 (uefi runtime data:) [ 0.000000] memory[0x6] [0x000000fe870000-0x000000fe8bffff], 0x50000 bytes flags: 0x4 [ 0.000000] memory[0x7] [0x000000fe8c0000-0x000000feffffff], 0x740000 bytes flags: 0x0 [ 0.000000] memory[0x8] [0x00000880000000-0x000009ffffffff], 0x180000000 bytes flags: 0x0 [ 0.000000] reserved.cnt = 0x2 (uefi memory map:) [ 0.000000] reserved[0x0] [0x000000f985a000-0x000000f985afff], 0x1000 bytes flags: 0x0 (device tree:) [ 0.000000] reserved[0x1] [0x000009e0ce0000-0x000009e0ce3f3a], 0x3f3b bytes flags: 0x0 crash kernel memblock after call to memblock_cap_memory_range(): [ 0.000000] MEMBLOCK configuration: [ 0.000000] memory size = 0x20440000 reserved size = 0x3f3b [ 0.000000] memory.cnt = 0x4 [ 0.000000] memory[0x0] [0x000000f94a0000-0x000000f984ffff], 0x3b0000 bytes flags: 0x4 [ 0.000000] memory[0x1] [0x000000fe820000-0x000000fe85ffff], 0x40000 bytes flags: 0x4 [ 0.000000] memory[0x2] [0x000000fe870000-0x000000fe8bffff], 0x50000 bytes flags: 0x4 [ 0.000000] memory[0x3] [0x000009e0000000-0x000009ffffffff], 0x20000000 bytes flags: 0x0 [ 0.000000] reserved.cnt = 0x1 [ 0.000000] reserved[0x0] [0x000009e0ce0000-0x000009e0ce3f3a], 0x3f3b bytes flags: 0x0 (reserve kernel text:) [ 0.000000] memblock_reserve: [0x000009e0080000-0x000009e0cd0fff] flags 0x0 arm64_memblock_init+0x1e0/0x40c (reserve elfcorehdr:) [ 0.000000] memblock_reserve: [0x000009fffff000-0x000009fffff3ff] flags 0x0 arm64_memblock_init+0x37c/0x40c [ 0.000000] Reserving 1KB of memory at 0x9fffff000 for elfcorehdr [ 0.000000] cma: Failed to reserve 16 MiB ... It looks like memblock_cap_memory_range() did exactly what you intended This first fault seems to be because memblock_start_of_DRAM() is being dragged down by the preserved nomap areas, this means there isn't any usable memory within ~4G of memblock_start_of_DRAM()... I will dig into the bootmem alloc failure next week... (let me know if you want the full boot logs... they are more noise than signal) Thanks, James
