4.17-stable review patch. If anyone has any objections, please let me know.
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From: Pavel Tatashin pasha.tatashin@oracle.com
commit d1b47a7c9efcf3c3384b70f6e3c8f1423b44d8c7 upstream.
Moving zero_resv_unavail before memmap_init_zone(), caused a regression on x86-32.
The cause is that we access struct pages before they are allocated when CONFIG_FLAT_NODE_MEM_MAP is used.
free_area_init_nodes() zero_resv_unavail() mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced free_area_init_node() if CONFIG_FLAT_NODE_MEM_MAP alloc_node_mem_map() memblock_virt_alloc_node_nopanic() <- struct page alloced here
On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory that it returns, so we do not need to do zero_resv_unavail() here.
Fixes: e181ae0c5db9 ("mm: zero unavailable pages before memmap init") Signed-off-by: Pavel Tatashin pasha.tatashin@oracle.com Tested-by: Matt Hart matt@mattface.org Acked-by: Michal Hocko mhocko@suse.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/mm.h | 2 +- mm/page_alloc.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
--- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2081,7 +2081,7 @@ extern int __meminit __early_pfn_to_nid( struct mminit_pfnnid_cache *state); #endif
-#ifdef CONFIG_HAVE_MEMBLOCK +#if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP) void zero_resv_unavail(void); #else static inline void zero_resv_unavail(void) {} --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6377,7 +6377,7 @@ void __paginginit free_area_init_node(in free_area_init_core(pgdat); }
-#ifdef CONFIG_HAVE_MEMBLOCK +#if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP) /* * Only struct pages that are backed by physical memory are zeroed and * initialized by going through __init_single_page(). But, there are some @@ -6415,7 +6415,7 @@ void __paginginit zero_resv_unavail(void if (pgcnt) pr_info("Reserved but unavailable: %lld pages", pgcnt); } -#endif /* CONFIG_HAVE_MEMBLOCK */ +#endif /* CONFIG_HAVE_MEMBLOCK && !CONFIG_FLAT_NODE_MEM_MAP */
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP