Re: [PATCH v2 3/6] mm/mm_init.c: add new function calc_nr_all_pages()

Mike Rapoport
2024-03-27T15:40:59Z

On Mon, Mar 25, 2024 at 10:56:43PM +0800, Baoquan He wrote:
> This is a preparation to calculate nr_kernel_pages and nr_all_pages,
> both of which will be used later in alloc_large_system_hash().
>
> nr_all_pages counts up all free but not reserved memory in memblock
> allocator, including HIGHMEM memory. While nr_kernel_pages counts up
> all free but not reserved low memory in memblock allocator, excluding
> HIGHMEM memory.
>
> Signed-off-by: Baoquan He <bhe@redhat.com>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
> mm/mm_init.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 153fb2dc666f..c57a7fc97a16 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -1264,6 +1264,30 @@ static void __init reset_memoryless_node_totalpages(struct pglist_data *pgdat)
> pr_debug("On node %d totalpages: 0\n", pgdat->node_id);
> }
>
> +static void __init calc_nr_kernel_pages(void)
> +{
> + unsigned long start_pfn, end_pfn;
> + phys_addr_t start_addr, end_addr;
> + u64 u;
> +#ifdef CONFIG_HIGHMEM
> + unsigned long high_zone_low = arch_zone_lowest_possible_pfn[ZONE_HIGHMEM];
> +#endif
> +
> + for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start_addr, &end_addr, NULL) {
> + start_pfn = PFN_UP(start_addr);
> + end_pfn = PFN_DOWN(end_addr);
> +
> + if (start_pfn < end_pfn) {
> + nr_all_pages += end_pfn - start_pfn;
> +#ifdef CONFIG_HIGHMEM
> + start_pfn = clamp(start_pfn, 0, high_zone_low);
> + end_pfn = clamp(end_pfn, 0, high_zone_low);
> +#endif
> + nr_kernel_pages += end_pfn - start_pfn;
> + }
> + }
> +}
> +
> static void __init calculate_node_totalpages(struct pglist_data *pgdat,
> unsigned long node_start_pfn,
> unsigned long node_end_pfn)
> --
> 2.41.0
>

--
Sincerely yours,
Mike.