Re: [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node()

[Shahab Vahedi]

On 10/4/21 11:36 AM, David Hildenbrand wrote:
> We want to specify flags when hotplugging memory. Let's prepare to pass
> flags to memblock_add_node() by adjusting all existing users.
> 
> Note that when hotplugging memory the system is already up and running
> and we might have concurrent memblock users: for example, while we're
> hotplugging memory, kexec_file code might search for suitable memory
> regions to place kexec images. It's important to add the memory directly
> to memblock via a single call with the right flags, instead of adding the
> memory first and apply flags later: otherwise, concurrent memblock users
> might temporarily stumble over memblocks with wrong flags, which will be
> important in a follow-up patch that introduces a new flag to properly
> handle add_memory_driver_managed().
> 
> Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
>  arch/arc/mm/init.c               | 4 ++--
>  arch/ia64/mm/contig.c            | 2 +-
>  arch/ia64/mm/init.c              | 2 +-
>  arch/m68k/mm/mcfmmu.c            | 3 ++-
>  arch/m68k/mm/motorola.c          | 6 ++++--
>  arch/mips/loongson64/init.c      | 4 +++-
>  arch/mips/sgi-ip27/ip27-memory.c | 3 ++-
>  arch/s390/kernel/setup.c         | 3 ++-
>  include/linux/memblock.h         | 3 ++-
>  include/linux/mm.h               | 2 +-
>  mm/memblock.c                    | 9 +++++----
>  mm/memory_hotplug.c              | 2 +-
>  12 files changed, 26 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> index 699ecf119641..110eb69e9bee 100644
> --- a/arch/arc/mm/init.c
> +++ b/arch/arc/mm/init.c
> @@ -59,13 +59,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
>  
>  		low_mem_sz = size;
>  		in_use = 1;
> -		memblock_add_node(base, size, 0);
> +		memblock_add_node(base, size, 0, MEMBLOCK_NONE);
>  	} else {
>  #ifdef CONFIG_HIGHMEM
>  		high_mem_start = base;
>  		high_mem_sz = size;
>  		in_use = 1;
> -		memblock_add_node(base, size, 1);
> +		memblock_add_node(base, size, 1, MEMBLOCK_NONE);
>  		memblock_reserve(base, size);
>  #endif

arch/arc part: Acked-by: Shahab Vahedi <shahab@xxxxxxxxxxxx>

-- 
Shahab