On Wed, 14 Jul 2021 15:37:38 +0300 Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> There are several places that allocate memory for the memory map:
> alloc_node_mem_map() for FLATMEM, sparse_buffer_init() and
> __populate_section_memmap() for SPARSEMEM.
>
> The memory allocated in the FLATMEM case is zeroed and it is never
> poisoned, regardless of CONFIG_PAGE_POISON setting.
>
> The memory allocated in the SPARSEMEM cases is not zeroed and it is
> implicitly poisoned inside memblock if CONFIG_PAGE_POISON is set.
>
> Introduce memmap_alloc() wrapper for memblock allocators that will be used
> for both FLATMEM and SPARSEMEM cases and will makei memory map zeroing and
> poisoning consistent for different memory models.
>
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -6730,6 +6730,26 @@ static void __init memmap_init(void)
> init_unavailable_range(hole_pfn, end_pfn, zone_id, nid);
> }
>
> +void __init *memmap_alloc(phys_addr_t size, phys_addr_t align,
> + phys_addr_t min_addr, int nid, bool exact_nid)
> +{
> + void *ptr;
> +
> + if (exact_nid)
> + ptr = memblock_alloc_exact_nid_raw(size, align, min_addr,
> + MEMBLOCK_ALLOC_ACCESSIBLE,
> + nid);
> + else
> + ptr = memblock_alloc_try_nid_raw(size, align, min_addr,
> + MEMBLOCK_ALLOC_ACCESSIBLE,
> + nid);
> +
> + if (ptr && size > 0)
> + page_init_poison(ptr, size);
> +
> + return ptr;
> +}
> +
> static int zone_batchsize(struct zone *zone)
> {
> #ifdef CONFIG_MMU
> @@ -7501,8 +7521,8 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
> end = pgdat_end_pfn(pgdat);
> end = ALIGN(end, MAX_ORDER_NR_PAGES);
> size = (end - start) * sizeof(struct page);
> - map = memblock_alloc_node(size, SMP_CACHE_BYTES,
> - pgdat->node_id);
> + map = memmap_alloc(size, SMP_CACHE_BYTES, MEMBLOCK_LOW_LIMIT,
> + pgdat->node_id, false);
Mostly offtopic, but... Why is alloc_node_mem_map() marked __ref?
afaict it can be __init?
