On Tue, Mar 26, 2024 at 02:11:28PM +0800, Baoquan He wrote:
> Because memory-less node's ->node_present_pages and its
> zone's ->present_pages are all 0, the judgement before calling
> node_set_state() to set N_MEMORY, N_HIGH_MEMORY, N_NORMAL_MEMORY for
> node is enough to skip memory-less node. The 'continue;' statement
> inside for_each_node() loop of free_area_init() is gilding the lily.
>
> Here, remove the special handling to make memory-less node share the
> same code flow as normal node. And the code comment above the 'continue'
> statement is not needed either.
>
> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> ---
> mm/mm_init.c | 18 +++---------------
> 1 file changed, 3 insertions(+), 15 deletions(-)
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 089dc60159e9..99681ffb9091 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -1834,28 +1834,16 @@ void __init free_area_init(unsigned long *max_zone_pfn)
> panic("Cannot allocate %zuB for node %d.\n",
> sizeof(*pgdat), nid);
> arch_refresh_nodedata(nid, pgdat);
> - free_area_init_node(nid);
> -
> - /*
> - * We do not want to confuse userspace by sysfs
> - * files/directories for node without any memory
> - * attached to it, so this node is not marked as
> - * N_MEMORY and not marked online so that no sysfs
> - * hierarchy will be created via register_one_node for
> - * it. The pgdat will get fully initialized by
> - * hotadd_init_pgdat() when memory is hotplugged into
> - * this node.
> - */
I think this comment is still valuable. Maybe rephrase it a bit and move it
before 'if (pgdat->node_present_pages)'?
> - continue;
> }
>
> pgdat = NODE_DATA(nid);
> free_area_init_node(nid);
>
> /* Any memory on that node */
> - if (pgdat->node_present_pages)
> + if (pgdat->node_present_pages) {
> node_set_state(nid, N_MEMORY);
> - check_for_memory(pgdat);
> + check_for_memory(pgdat);
> + }
> }
>
> calc_nr_kernel_pages();
> --
> 2.41.0
>
--
Sincerely yours,
Mike.
