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

Shahab Vahedi
2021-10-04T19:32:03Z

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@linux-m68k.org>
> Acked-by: Heiko Carstens <hca@linux.ibm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> 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@synopsys.com>

--
Shahab