Re: [PATCH v2] x86/mm: Remove the redundant conditional check

From: Michal Hocko
Date: Wed Mar 11 2020 - 05:27:23 EST


On Wed 11-03-20 09:18:23, Baoquan He wrote:
> In commit f70029bbaacb ("mm, memory_hotplug: drop CONFIG_MOVABLE_NODE"),
> the dependency on CONFIG_MOVABLE_NODE was removed for N_MEMORY. Before
> commit f70029bbaacb, CONFIG_HIGHMEM && !CONFIG_MOVABLE_NODE could make
> (N_MEMORY == N_NORMAL_MEMORY) be true. After commit f70029bbaacb, N_MEMORY
> doesn't have any chance to be equal to N_NORMAL_MEMORY. So the conditional
> check in paging_init() doesn't make sense any more. Let's remove it.
>
> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!

> ---
> v1->v2:
> Update patch log to make the description clearer per Michal's
> suggestion.
>
> arch/x86/mm/init_64.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index abbdecb75fad..0a14711d3a93 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -818,8 +818,7 @@ void __init paging_init(void)
> * will not set it back.
> */
> node_clear_state(0, N_MEMORY);
> - if (N_MEMORY != N_NORMAL_MEMORY)
> - node_clear_state(0, N_NORMAL_MEMORY);
> + node_clear_state(0, N_NORMAL_MEMORY);
>
> zone_sizes_init();
> }
> --
> 2.17.2

--
Michal Hocko
SUSE Labs