'mem=" option is an easy way to put high pressure on memory during some test. Hence in stead of total mem, the effective usable memory size should be considered when reserving mem for crashkernel. Otherwise the boot up may experience oom issue.
E.g passing crashkernel="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G", and mem=5G on a 256G machine. Signed-off-by: Pingfan Liu <kernelf...@gmail.com> Cc: Hari Bathini <hbath...@linux.ibm.com> Cc: Michael Ellerman <m...@ellerman.id.au> To: linuxppc-dev@lists.ozlabs.org --- v1 -> v2: fix the printk info about the total mem arch/powerpc/kernel/machine_kexec.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c index c4ed328..eec96dc 100644 --- a/arch/powerpc/kernel/machine_kexec.c +++ b/arch/powerpc/kernel/machine_kexec.c @@ -114,11 +114,12 @@ void machine_kexec(struct kimage *image) void __init reserve_crashkernel(void) { - unsigned long long crash_size, crash_base; + unsigned long long crash_size, crash_base, total_mem_sz; int ret; + total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); /* use common parsing */ - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), + ret = parse_crashkernel(boot_command_line, total_mem_sz, &crash_size, &crash_base); if (ret == 0 && crash_size > 0) { crashk_res.start = crash_base; @@ -185,7 +186,7 @@ void __init reserve_crashkernel(void) "for crashkernel (System RAM: %ldMB)\n", (unsigned long)(crash_size >> 20), (unsigned long)(crashk_res.start >> 20), - (unsigned long)(memblock_phys_mem_size() >> 20)); + (unsigned long)(total_mem_sz >> 20)); if (!memblock_is_region_memory(crashk_res.start, crash_size) || memblock_reserve(crashk_res.start, crash_size)) { -- 2.7.5