Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "190 patches.

  Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
  vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
  migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
  zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
  core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
  signals, exec, kcov, selftests, compress/decompress, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  ipc/util.c: use binary search for max_idx
  ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
  ipc: use kmalloc for msg_queue and shmid_kernel
  ipc sem: use kvmalloc for sem_undo allocation
  lib/decompressors: remove set but not used variabled 'level'
  selftests/vm/pkeys: exercise x86 XSAVE init state
  selftests/vm/pkeys: refill shadow register after implicit kernel write
  selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
  selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
  kcov: add __no_sanitize_coverage to fix noinstr for all architectures
  exec: remove checks in __register_bimfmt()
  x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
  hfsplus: report create_date to kstat.btime
  hfsplus: remove unnecessary oom message
  nilfs2: remove redundant continue statement in a while-loop
  kprobes: remove duplicated strong free_insn_page in x86 and s390
  init: print out unknown kernel parameters
  checkpatch: do not complain about positive return values starting with EPOLL
  checkpatch: improve the indented label test
  checkpatch: scripts/spdxcheck.py now requires python3
  ...

1 files changed, 18 insertions, 2 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d7c3cb8688dd..4620df62f0ff 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1499,7 +1499,8 @@ static unsigned int shrink_page_list(struct list_head *page_list,
 			if (unlikely(PageTransHuge(page)))
 				flags |= TTU_SPLIT_HUGE_PMD;
 
-			if (!try_to_unmap(page, flags)) {
+			try_to_unmap(page, flags);
+			if (page_mapped(page)) {
 				stat->nr_unmap_fail += nr_pages;
 				if (!was_swapbacked && PageSwapBacked(page))
 					stat->nr_lazyfree_fail += nr_pages;
@@ -1701,6 +1702,7 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 	unsigned int nr_reclaimed;
 	struct page *page, *next;
 	LIST_HEAD(clean_pages);
+	unsigned int noreclaim_flag;
 
 	list_for_each_entry_safe(page, next, page_list, lru) {
 		if (!PageHuge(page) && page_is_file_lru(page) &&
@@ -1711,8 +1713,17 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 		}
 	}
 
+	/*
+	 * We should be safe here since we are only dealing with file pages and
+	 * we are not kswapd and therefore cannot write dirty file pages. But
+	 * call memalloc_noreclaim_save() anyway, just in case these conditions
+	 * change in the future.
+	 */
+	noreclaim_flag = memalloc_noreclaim_save();
 	nr_reclaimed = shrink_page_list(&clean_pages, zone->zone_pgdat, &sc,
 					&stat, true);
+	memalloc_noreclaim_restore(noreclaim_flag);
+
 	list_splice(&clean_pages, page_list);
 	mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE,
 			    -(long)nr_reclaimed);
@@ -1810,7 +1821,7 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec,
 
 }
 
-/**
+/*
  * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
  *
  * lruvec->lru_lock is heavily contended.  Some of the functions that
@@ -2306,6 +2317,7 @@ unsigned long reclaim_pages(struct list_head *page_list)
 	LIST_HEAD(node_page_list);
 	struct reclaim_stat dummy_stat;
 	struct page *page;
+	unsigned int noreclaim_flag;
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
 		.priority = DEF_PRIORITY,
@@ -2314,6 +2326,8 @@ unsigned long reclaim_pages(struct list_head *page_list)
 		.may_swap = 1,
 	};
 
+	noreclaim_flag = memalloc_noreclaim_save();
+
 	while (!list_empty(page_list)) {
 		page = lru_to_page(page_list);
 		if (nid == NUMA_NO_NODE) {
@@ -2350,6 +2364,8 @@ unsigned long reclaim_pages(struct list_head *page_list)
 		}
 	}
 
+	memalloc_noreclaim_restore(noreclaim_flag);
+
 	return nr_reclaimed;
 }