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
  ...

1 files changed, 20 insertions, 5 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index 8c49d09da214..cf04bc3c866c 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -821,13 +821,28 @@ config PERCPU_STATS
 	  information includes global and per chunk statistics, which can
 	  be used to help understand percpu memory usage.
 
-config GUP_BENCHMARK
-	bool "Enable infrastructure for get_user_pages() and related calls benchmarking"
+config GUP_TEST
+	bool "Enable infrastructure for get_user_pages()-related unit tests"
+	depends on DEBUG_FS
 	help
-	  Provides /sys/kernel/debug/gup_benchmark that helps with testing
-	  performance of get_user_pages() and related calls.
+	  Provides /sys/kernel/debug/gup_test, which in turn provides a way
+	  to make ioctl calls that can launch kernel-based unit tests for
+	  the get_user_pages*() and pin_user_pages*() family of API calls.
 
-	  See tools/testing/selftests/vm/gup_benchmark.c
+	  These tests include benchmark testing of the _fast variants of
+	  get_user_pages*() and pin_user_pages*(), as well as smoke tests of
+	  the non-_fast variants.
+
+	  There is also a sub-test that allows running dump_page() on any
+	  of up to eight pages (selected by command line args) within the
+	  range of user-space addresses. These pages are either pinned via
+	  pin_user_pages*(), or pinned via get_user_pages*(), as specified
+	  by other command line arguments.
+
+	  See tools/testing/selftests/vm/gup_test.c
+
+comment "GUP_TEST needs to have DEBUG_FS enabled"
+	depends on !GUP_TEST && !DEBUG_FS
 
 config GUP_GET_PTE_LOW_HIGH
 	bool