Merge tag 'v5.9-rc7' into patchwork

Linux 5.9-rc7

* tag 'v5.9-rc7': (683 commits)
  Linux 5.9-rc7
  mm/thp: Split huge pmds/puds if they're pinned when fork()
  mm: Do early cow for pinned pages during fork() for ptes
  mm/fork: Pass new vma pointer into copy_page_range()
  mm: Introduce mm_struct.has_pinned
  mm: validate pmd after splitting
  mm: don't rely on system state to detect hot-plug operations
  mm: replace memmap_context by meminit_context
  arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
  lib/memregion.c: include memregion.h
  lib/string.c: implement stpcpy
  mm/migrate: correct thp migration stats
  mm/gup: fix gup_fast with dynamic page table folding
  mm: memcontrol: fix missing suffix of workingset_restore
  mm, THP, swap: fix allocating cluster for swapfile by mistake
  mm: slab: fix potential double free in ___cache_free
  Documentation/llvm: Fix clang target examples
  io_uring: ensure async buffered read-retry is setup properly
  KVM: SVM: Add a dedicated INVD intercept routine
  io_uring: don't unconditionally set plug->nowait = true
  ...

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 496c3ff97cce..ed028af3cb19 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -436,6 +436,16 @@ struct mm_struct {
 		 */
 		atomic_t mm_count;
 
+		/**
+		 * @has_pinned: Whether this mm has pinned any pages.  This can
+		 * be either replaced in the future by @pinned_vm when it
+		 * becomes stable, or grow into a counter on its own. We're
+		 * aggresive on this bit now - even if the pinned pages were
+		 * unpinned later on, we'll still keep this bit set for the
+		 * lifecycle of this mm just for simplicity.
+		 */
+		atomic_t has_pinned;
+
 #ifdef CONFIG_MMU
 		atomic_long_t pgtables_bytes;	/* PTE page table pages */
 #endif