Subject: Re: [PATCH] powerpc/kdump: handle crashkernel memory reservation failure

From: David Gibson <[email-masked]>
Date: Thu, 28 Jun 2018 15:32:56 +1000

On Thu, 28 Jun 2018 10:49:56 +0530
Hari Bathini <[email-masked]> wrote:

> Memory reservation for crashkernel could fail if there are holes around
> kdump kernel offset (128M). Fail gracefully in such cases and print an
> error message.
> 
> Signed-off-by: Hari Bathini <[email-masked]>

Tested-by: David Gibson <[email-masked]>

> ---
>  arch/powerpc/kernel/machine_kexec.c |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
> index 936c7e2..6181442 100644
> --- a/arch/powerpc/kernel/machine_kexec.c
> +++ b/arch/powerpc/kernel/machine_kexec.c
> @@ -188,7 +188,12 @@ void __init reserve_crashkernel(void)
>  			(unsigned long)(crashk_res.start >> 20),
>  			(unsigned long)(memblock_phys_mem_size() >> 20));
>  
> -	memblock_reserve(crashk_res.start, crash_size);
> +	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
> +	    memblock_reserve(crashk_res.start, crash_size)) {
> +		printk(KERN_ERR "Failed to reserve memory for crashkernel!\n");
> +		crashk_res.start = crashk_res.end = 0;
> +		return;
> +	}
>  }
>  
>  int overlaps_crashkernel(unsigned long start, unsigned long size)
> 

-- 
David Gibson <[email-masked]>
Principal Software Engineer, Virtualization, Red Hat