Re: [PATCH v4 5/5] x86: implement crashkernel cma reservation

From: Jiri Bohac
Date: Tue Jun 03 2025 - 08:12:05 EST


On Tue, Jun 03, 2025 at 07:02:06PM +0800, Baoquan He wrote:
> On 05/30/25 at 10:31pm, Jiri Bohac wrote:
> ......snip..
> > @@ -582,7 +582,7 @@ static void __init arch_reserve_crashkernel(void)
> >
> > ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
> > &crash_size, &crash_base,
> > - &low_size, NULL, &high);
> > + &low_size, &cma_size, &high);
> > if (ret)
> > return;
> >
> > @@ -592,6 +592,7 @@ static void __init arch_reserve_crashkernel(void)
> > }
> >
> > reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
> > + reserve_crashkernel_cma(cma_size);
>
> Wondering if ,high|low is still allowed (or needed) when ,cma is specified.

Probably not needed but it works, totally independent of the
extra CMA-reserved area.

I saw no reason to artificially prevent it.

--
Jiri Bohac <jbohac@xxxxxxx>
SUSE Labs, Prague, Czechia