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@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/internal.h b/mm/internal.h
index 31ff935..57e2826 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -211,6 +211,10 @@ extern void zone_pcp_reset(struct zone *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
 
 /*

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd2efd6..71ad97c 100644 (file)
--- a/mm/page_alloc.c
+++ b/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(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);
                if (!map)
                        panic("Failed to allocate %ld bytes for node %d memory map\n",
                              size, pgdat->node_id);

diff --git a/mm/sparse.c b/mm/sparse.c
index fd29b3a..120bc8e 100644 (file)
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -436,8 +436,7 @@ struct page __init *__populate_section_memmap(unsigned long pfn,
        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(unsigned long size, int nid)
         * 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;
 }