Re: [PATCH v12 3/9] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel[_low]()

[Dave Young]

On 09/18/20 at 11:57am, chenzhou wrote:
> Hi Dave,
> 
> 
> On 2020/9/18 11:01, Dave Young wrote:
> > On 09/07/20 at 09:47pm, Chen Zhou wrote:
> >> To make the functions reserve_crashkernel[_low]() as generic,
> >> replace some hard-coded numbers with macro CRASH_ADDR_LOW_MAX.
> >>
> >> Signed-off-by: Chen Zhou <chenzhou10@xxxxxxxxxx>
> >> ---
> >>  arch/x86/kernel/setup.c | 11 ++++++-----
> >>  1 file changed, 6 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> >> index d7fd90c52dae..71a6a6e7ca5b 100644
> >> --- a/arch/x86/kernel/setup.c
> >> +++ b/arch/x86/kernel/setup.c
> >> @@ -430,7 +430,7 @@ static int __init reserve_crashkernel_low(void)
> >>  	unsigned long total_low_mem;
> >>  	int ret;
> >>  
> >> -	total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
> >> +	total_low_mem = memblock_mem_size(CRASH_ADDR_LOW_MAX >> PAGE_SHIFT);
> > total_low_mem != CRASH_ADDR_LOW_MAX
> I just replace the magic number with macro, no other change.
> Besides, function memblock_mem_size(limit_pfn) will compute the memory size
> according to the actual system ram.
> 

Ok, it is not obvious in patch this is 64bit only, I'm fine with this
then.