Re: [PATCH 1/2] arm64, kdump: enforce to take 4G as the crashkernel low memory end

From: Baoquan He
Date: Mon Sep 05 2022 - 08:08:38 EST


On 09/05/22 at 01:28pm, Mike Rapoport wrote:
> On Thu, Sep 01, 2022 at 08:25:54PM +0800, Baoquan He wrote:
> > On 09/01/22 at 10:24am, Mike Rapoport wrote:
> >
> > max_zone_phys() only handles cases when CONFIG_ZONE_DMA/DMA32 enabled,
> > the disabledCONFIG_ZONE_DMA/DMA32 case is not included. I can change
> > it like:
> >
> > static phys_addr_t __init crash_addr_low_max(void)
> > {
> > phys_addr_t low_mem_mask = U32_MAX;
> > phys_addr_t phys_start = memblock_start_of_DRAM();
> >
> > if ((!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) ||
> > (phys_start > U32_MAX))
> > low_mem_mask = PHYS_ADDR_MAX;
> >
> > return low_mem_mast + 1;
> > }
> >
> > or add the disabled CONFIG_ZONE_DMA/DMA32 case into crash_addr_low_max()
> > as you suggested. Which one do you like better?
> >
> > static phys_addr_t __init crash_addr_low_max(void)
> > {
> > if (!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32))
> > return PHYS_ADDR_MAX + 1;
> >
> > return max_zone_phys(32);
> > }
>
> I like the second variant better.

Sure, will change to use the 2nd one . Thanks.