[PATCH v3 15/17] crash: Simplify CRASH_MAX_MEMORY_RANGES handling

Mike Rapoport rppt at kernel.org
Tue Sep 1 13:14:00 PDT 2026


Hi,

> Set CRASH_MAX_MEMORY_RANGES to 0 when MEMORY_HOTPLUG is disabled, then
> remove the now unnecessary IS_ENABLED(CONFIG_MEMORY_HOTPLUG) checks in
> powerpc and x86 arch_crash_get_elfcorehdr_size().
> 
> No functional change intended.
> 
> Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>
>
> diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
> index fc0105c7af4c3..c47e3f867ea1f 100644
> --- a/arch/powerpc/kexec/crash.c
> +++ b/arch/powerpc/kexec/crash.c
> @@ -474,9 +474,7 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
>  	unsigned long phdr_cnt;
>  
>  	/* A program header for possible CPUs + vmcoreinfo */
> -	phdr_cnt = num_possible_cpus() + 1;
> -	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
> -		phdr_cnt += CONFIG_CRASH_MAX_MEMORY_RANGES;
> +	phdr_cnt = num_possible_cpus() + 1 + CONFIG_CRASH_MAX_MEMORY_RANGES;
>  
>  	return elf64_phdr_size(phdr_cnt);
>  }
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index 99eb8583d9321..116410ac90fb4 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -407,9 +407,7 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
>  	unsigned int sz;
>  
>  	/* kernel_map, VMCOREINFO and maximum CPUs */
> -	sz = 2 + num_possible_cpus();
> -	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
> -		sz += CONFIG_CRASH_MAX_MEMORY_RANGES;
> +	sz = 2 + num_possible_cpus() + CONFIG_CRASH_MAX_MEMORY_RANGES;
>  	sz *= sizeof(Elf64_Phdr);
>  	return sz;
>  }
> diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
> index a97ed9605602f..e6251dfe451a8 100644
> --- a/kernel/Kconfig.kexec
> +++ b/kernel/Kconfig.kexec
> @@ -160,7 +160,8 @@ config CRASH_HOTPLUG
>  
>  config CRASH_MAX_MEMORY_RANGES
>  	int "Specify the maximum number of memory regions for the elfcorehdr"
> -	default 8192
> +	default 8192 if MEMORY_HOTPLUG
> +	default 0 if !MEMORY_HOTPLUG

This only sets the default, but a user can change the value explicitly.

-- 
Sincerely yours,
Mike.




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