Hi Pratyush, On 04/02/2015 12:56 AM, Pratyush Anand wrote: > Hi Akashi, > > On Thursday 26 March 2015 01:58 PM, AKASHI Takahiro wrote: >> This patch set enables kdump (crash dump kernel) support on arm64 on top of >> Geoff's kexec patchset. >> >> In this version, there are some arm64-specific usage/constraints: >> 1) "mem=" boot parameter must be specified on crash dump kernel >> 2) Kvm will not be enabled on crash dump kernel even if configured >> See commit messages and Documentation/kdump/kdump.txt for details. >> >> The only concern I have is whether or not we can use the exact same kernel >> as both system kernel and crash dump kernel. The current arm64 kernel is >> not relocatable in the exact sense but I have no problems in using the same >> binary for testing kdump. >> >> I tested the code with >> - ATF v1.1 + EDK2(UEFI) v3.0-rc0 >> - kernel v4.0-rc4 + Geoff' kexec v8 >> on Base fast model, using my yet-to-be-submitted kexec-tools [1]. >> You may want to start a kernel with the following boot parameter: >> crashkernel=64M at 2240M >> and try >> $ kexec -p --load <vmlinux> --append ... >> $ echo c > /proc/sysrq-trigger >> > > I tried to use your kdump patches for kernel and kexec-tools. I am not able to load the crash kernel properly. > > > I passed crashkernel=64M at 259G (My 8GB RAM starts at 256G) to primary kernel. > > Used following to load the crash kernel > kexec -p --load vmlinux --append="$( cat /proc/cmdline ) maxcpus=1 mem=64M reset_devices" > > I see: > > kexec_load failed: Cannot assign requested address > entry = 0x40c40005d0 flags = 0xb70001 > > What I noticed that arm64_load_other_segments does not calculate correct load address for purgatory or if I pass initrd > then for that too within crash kernel allocated memory. It seems that you hit the same problem that I mentioned in: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/334613.html Please try my latest kexec-tools in my linaro repo (branch name is kdump/v0.11) and let me know the result. > Shouldn't we have a function similar to locate_dtb_in_crashmem for putgatory as well as initrd? I can try to fix this > allocation, but I was just wondering if I understood correctly or I am missing something. I don't think a function for purgatory is necessary since we try to find a hole just after dtb. Thanks, -Takahiro AKASHI > ~Pratyush > > >> To examine vmcore (/proc/vmcore), you may use >> - gdb v7.7 or later >> - crash + a small patch (to recognize v4.0 kernel) >> >> [1] https://git.linaro.org/people/takahiro.akashi/kexec-tools.git >> >> >> AKASHI Takahiro (5): >> arm64: kdump: reserve memory for crash dump kernel >> arm64: kdump: implement machine_crash_shutdown() >> arm64: kdump: do not go into EL2 before starting a crash dump kernel >> arm64: add kdump support >> arm64: enable kdump in the arm64 defconfig >> >> Documentation/kdump/kdump.txt | 31 ++++++++++++++- >> arch/arm64/Kconfig | 12 ++++++ >> arch/arm64/configs/defconfig | 1 + >> arch/arm64/include/asm/kexec.h | 34 +++++++++++++++- >> arch/arm64/kernel/Makefile | 1 + >> arch/arm64/kernel/crash_dump.c | 71 +++++++++++++++++++++++++++++++++ >> arch/arm64/kernel/machine_kexec.c | 55 +++++++++++++++++++++++++- >> arch/arm64/kernel/process.c | 7 +++- >> arch/arm64/kernel/setup.c | 78 +++++++++++++++++++++++++++++++++++++ >> arch/arm64/kernel/smp.c | 10 ++++- >> 10 files changed, 294 insertions(+), 6 deletions(-) >> create mode 100644 arch/arm64/kernel/crash_dump.c >>
