Merge tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "There is no particular theme here - mainly quick hits all over the
  tree.

  Most notable is a set of zlib changes from Mikhail Zaslonko which
  enhances and fixes zlib's use of S390 hardware support: 'lib/zlib: Set
  of s390 DFLTCC related patches for kernel zlib'"

* tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (55 commits)
  Update CREDITS file entry for Jesper Juhl
  sparc: allow PM configs for sparc32 COMPILE_TEST
  hung_task: print message when hung_task_warnings gets down to zero.
  arch/Kconfig: fix indentation
  scripts/tags.sh: fix the Kconfig tags generation when using latest ctags
  nilfs2: prevent WARNING in nilfs_dat_commit_end()
  lib/zlib: remove redundation assignement of avail_in dfltcc_gdht()
  lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default
  lib/zlib: DFLTCC always switch to software inflate for Z_PACKET_FLUSH option
  lib/zlib: DFLTCC support inflate with small window
  lib/zlib: Split deflate and inflate states for DFLTCC
  lib/zlib: DFLTCC not writing header bits when avail_out == 0
  lib/zlib: fix DFLTCC ignoring flush modes when avail_in == 0
  lib/zlib: fix DFLTCC not flushing EOBS when creating raw streams
  lib/zlib: implement switching between DFLTCC and software
  lib/zlib: adjust offset calculation for dfltcc_state
  nilfs2: replace WARN_ONs for invalid DAT metadata block requests
  scripts/spelling.txt: add "exsits" pattern and fix typo instances
  fs: gracefully handle ->get_block not mapping bh in __mpage_writepage
  cramfs: Kconfig: fix spelling & punctuation
  ...

1 files changed, 39 insertions, 1 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2e91421e096e..c8b379e2e9ad 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1185,13 +1185,16 @@ config DEBUG_TIMEKEEPING
 config DEBUG_PREEMPT
 	bool "Debug preemptible kernel"
 	depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
-	default y
 	help
 	  If you say Y here then the kernel will use a debug variant of the
 	  commonly used smp_processor_id() function and will print warnings
 	  if kernel code uses it in a preemption-unsafe way. Also, the kernel
 	  will detect preemption count underflows.
 
+	  This option has potential to introduce high runtime overhead,
+	  depending on workload as it triggers debugging routines for each
+	  this_cpu operation. It should only be used for debugging purposes.
+
 menu "Lock Debugging (spinlocks, mutexes, etc...)"
 
 config LOCK_DEBUGGING_SUPPORT
@@ -2029,6 +2032,41 @@ menuconfig RUNTIME_TESTING_MENU
 
 if RUNTIME_TESTING_MENU
 
+config TEST_DHRY
+	tristate "Dhrystone benchmark test"
+	help
+	  Enable this to include the Dhrystone 2.1 benchmark.  This test
+	  calculates the number of Dhrystones per second, and the number of
+	  DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
+	  by 1757 (the number of Dhrystones per second obtained on the VAX
+	  11/780, nominally a 1 MIPS machine).
+
+	  To run the benchmark, it needs to be enabled explicitly, either from
+	  the kernel command line (when built-in), or from userspace (when
+	  built-in or modular.
+
+	  Run once during kernel boot:
+
+	      test_dhry.run
+
+	  Set number of iterations from kernel command line:
+
+	      test_dhry.iterations=<n>
+
+	  Set number of iterations from userspace:
+
+	      echo <n> > /sys/module/test_dhry/parameters/iterations
+
+	  Trigger manual run from userspace:
+
+	      echo y > /sys/module/test_dhry/parameters/run
+
+	  If the number of iterations is <= 0, the test will devise a suitable
+	  number of iterations (test runs for at least 2s) automatically.
+	  This process takes ca. 4s.
+
+	  If unsure, say N.
+
 config LKDTM
 	tristate "Linux Kernel Dump Test Tool Module"
 	depends on DEBUG_FS