Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
 "181 patches.

  Subsystems affected by this patch series: kbuild, scripts, ntfs,
  ocfs2, vfs, mm (slab, slub, kmemleak, dax, debug, pagecache, fadvise,
  gup, swap, memremap, memcg, selftests, pagemap, mincore, hmm, dma,
  memory-failure, vmallo and migration)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (181 commits)
  mm/migrate: remove obsolete comment about device public
  mm/migrate: remove cpages-- in migrate_vma_finalize()
  mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary
  memblock: use separate iterators for memory and reserved regions
  memblock: implement for_each_reserved_mem_region() using __next_mem_region()
  memblock: remove unused memblock_mem_size()
  x86/setup: simplify reserve_crashkernel()
  x86/setup: simplify initrd relocation and reservation
  arch, drivers: replace for_each_membock() with for_each_mem_range()
  arch, mm: replace for_each_memblock() with for_each_mem_pfn_range()
  memblock: reduce number of parameters in for_each_mem_range()
  memblock: make memblock_debug and related functionality private
  memblock: make for_each_memblock_type() iterator private
  mircoblaze: drop unneeded NUMA and sparsemem initializations
  riscv: drop unneeded node initialization
  h8300, nds32, openrisc: simplify detection of memory extents
  arm64: numa: simplify dummy_numa_init()
  arm, xtensa: simplify initialization of high memory pages
  dma-contiguous: simplify cma_early_percent_memory()
  KVM: PPC: Book3S HV: simplify kvm_cma_reserve()
  ...

1 files changed, 12 insertions, 9 deletions

diff --git a/mm/madvise.c b/mm/madvise.c
index 0e0d61003fc6..9b065d412e5f 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -224,25 +224,28 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma,
 		unsigned long start, unsigned long end,
 		struct address_space *mapping)
 {
-	pgoff_t index;
+	XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start));
+	pgoff_t end_index = end / PAGE_SIZE;
 	struct page *page;
-	swp_entry_t swap;
 
-	for (; start < end; start += PAGE_SIZE) {
-		index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+	rcu_read_lock();
+	xas_for_each(&xas, page, end_index) {
+		swp_entry_t swap;
 
-		page = find_get_entry(mapping, index);
-		if (!xa_is_value(page)) {
-			if (page)
-				put_page(page);
+		if (!xa_is_value(page))
 			continue;
-		}
+		xas_pause(&xas);
+		rcu_read_unlock();
+
 		swap = radix_to_swp_entry(page);
 		page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE,
 							NULL, 0, false);
 		if (page)
 			put_page(page);
+
+		rcu_read_lock();
 	}
+	rcu_read_unlock();
 
 	lru_add_drain();	/* Push any new pages onto the LRU now */
 }