Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...

2 files changed, 4 insertions, 70 deletions

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index fbd452e12397..69d4251ee079 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -444,71 +444,6 @@ void __init bootmem_init(void)
 	memblock_dump_all();
 }
 
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
-static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
-{
-	struct page *start_pg, *end_pg;
-	unsigned long pg, pgend;
-
-	/*
-	 * Convert start_pfn/end_pfn to a struct page pointer.
-	 */
-	start_pg = pfn_to_page(start_pfn - 1) + 1;
-	end_pg = pfn_to_page(end_pfn - 1) + 1;
-
-	/*
-	 * Convert to physical addresses, and round start upwards and end
-	 * downwards.
-	 */
-	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
-	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
-
-	/*
-	 * If there are free pages between these, free the section of the
-	 * memmap array.
-	 */
-	if (pg < pgend)
-		memblock_free(pg, pgend - pg);
-}
-
-/*
- * The mem_map array can get very big. Free the unused area of the memory map.
- */
-static void __init free_unused_memmap(void)
-{
-	unsigned long start, end, prev_end = 0;
-	int i;
-
-	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
-#ifdef CONFIG_SPARSEMEM
-		/*
-		 * Take care not to free memmap entries that don't exist due
-		 * to SPARSEMEM sections which aren't present.
-		 */
-		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
-#endif
-		/*
-		 * If we had a previous bank, and there is a space between the
-		 * current bank and the previous, free it.
-		 */
-		if (prev_end && prev_end < start)
-			free_memmap(prev_end, start);
-
-		/*
-		 * Align up here since the VM subsystem insists that the
-		 * memmap entries are valid from the bank end aligned to
-		 * MAX_ORDER_NR_PAGES.
-		 */
-		prev_end = ALIGN(end, MAX_ORDER_NR_PAGES);
-	}
-
-#ifdef CONFIG_SPARSEMEM
-	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
-		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
-#endif
-}
-#endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
-
 /*
  * mem_init() marks the free areas in the mem_map and tells us how much memory
  * is free.  This is done after various parts of the system have claimed their
@@ -524,9 +459,6 @@ void __init mem_init(void)
 
 	set_max_mapnr(max_pfn - PHYS_PFN_OFFSET);
 
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
-	free_unused_memmap();
-#endif
 	/* this will put all unused low memory onto the freelists */
 	memblock_free_all();
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 1b94f5b82654..92eccaf595c8 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -155,7 +155,7 @@ int set_direct_map_invalid_noflush(struct page *page)
 		.clear_mask = __pgprot(PTE_VALID),
 	};
 
-	if (!rodata_full)
+	if (!debug_pagealloc_enabled() && !rodata_full)
 		return 0;
 
 	return apply_to_page_range(&init_mm,
@@ -170,7 +170,7 @@ int set_direct_map_default_noflush(struct page *page)
 		.clear_mask = __pgprot(PTE_RDONLY),
 	};
 
-	if (!rodata_full)
+	if (!debug_pagealloc_enabled() && !rodata_full)
 		return 0;
 
 	return apply_to_page_range(&init_mm,
@@ -178,6 +178,7 @@ int set_direct_map_default_noflush(struct page *page)
 				   PAGE_SIZE, change_page_range, &data);
 }
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {
 	if (!debug_pagealloc_enabled() && !rodata_full)
@@ -185,6 +186,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
 
 	set_memory_valid((unsigned long)page_address(page), numpages, enable);
 }
+#endif /* CONFIG_DEBUG_PAGEALLOC */
 
 /*
  * This function is used to determine if a linear map page has been marked as