Re: [PATCH v14 02/11] x86: kdump: make the lower bound of crash kernel reservation consistent

From: Catalin Marinas
Date: Wed Feb 24 2021 - 10:15:16 EST


On Sat, Jan 30, 2021 at 03:10:16PM +0800, Chen Zhou wrote:
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index da769845597d..27470479e4a3 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -439,7 +439,8 @@ static int __init reserve_crashkernel_low(void)
> return 0;
> }
>
> - low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
> + low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, CRASH_ALIGN,
> + CRASH_ADDR_LOW_MAX);
> if (!low_base) {
> pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
> (unsigned long)(low_size >> 20));

Is there any reason why the lower bound can't be 0 in all low cases
here? (Sorry if it's been already discussed, I lost track)

--
Catalin