From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: mm: introduce memmap_alloc() to unify memory map allocation 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. Link: https://lkml.kernel.org/r/20210714123739.16493-4-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Michal Simek <monstr@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/internal.h | 4 ++++ mm/page_alloc.c | 24 ++++++++++++++++++++++-- mm/sparse.c | 6 ++---- 3 files changed, 28 insertions(+), 6 deletions(-) --- a/mm/internal.h~mm-introduce-memmap_alloc-to-unify-memory-map-allocation +++ a/mm/internal.h @@ -211,6 +211,10 @@ extern void zone_pcp_reset(struct zone * extern void zone_pcp_disable(struct zone *zone); extern void zone_pcp_enable(struct zone *zone); +extern void *memmap_alloc(phys_addr_t size, phys_addr_t align, + phys_addr_t min_addr, + int nid, bool exact_nid); + #if defined CONFIG_COMPACTION || defined CONFIG_CMA /* --- a/mm/page_alloc.c~mm-introduce-memmap_alloc-to-unify-memory-map-allocation +++ a/mm/page_alloc.c @@ -6748,6 +6748,26 @@ 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 @@ -7519,8 +7539,8 @@ static void __ref alloc_node_mem_map(str 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); if (!map) panic("Failed to allocate %ld bytes for node %d memory map\n", size, pgdat->node_id); --- a/mm/sparse.c~mm-introduce-memmap_alloc-to-unify-memory-map-allocation +++ a/mm/sparse.c @@ -436,8 +436,7 @@ struct page __init *__populate_section_m if (map) return map; - map = memblock_alloc_try_nid_raw(size, size, addr, - MEMBLOCK_ALLOC_ACCESSIBLE, nid); + map = memmap_alloc(size, size, addr, nid, false); if (!map) panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n", __func__, size, PAGE_SIZE, nid, &addr); @@ -464,8 +463,7 @@ static void __init sparse_buffer_init(un * and we want it to be properly aligned to the section size - this is * especially the case for VMEMMAP which maps memmap to PMDs */ - sparsemap_buf = memblock_alloc_exact_nid_raw(size, section_map_size(), - addr, MEMBLOCK_ALLOC_ACCESSIBLE, nid); + sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true); sparsemap_buf_end = sparsemap_buf + size; } _
