Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - the rest of MM

 - procfs updates

 - various misc things

 - more y2038 fixes

 - get_maintainer updates

 - lib/ updates

 - checkpatch updates

 - various epoll updates

 - autofs updates

 - hfsplus

 - some reiserfs work

 - fatfs updates

 - signal.c cleanups

 - ipc/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits)
  ipc/util.c: update return value of ipc_getref from int to bool
  ipc/util.c: further variable name cleanups
  ipc: simplify ipc initialization
  ipc: get rid of ids->tables_initialized hack
  lib/rhashtable: guarantee initial hashtable allocation
  lib/rhashtable: simplify bucket_table_alloc()
  ipc: drop ipc_lock()
  ipc/util.c: correct comment in ipc_obtain_object_check
  ipc: rename ipcctl_pre_down_nolock()
  ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()
  ipc: reorganize initialization of kern_ipc_perm.seq
  ipc: compute kern_ipc_perm.id under the ipc lock
  init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE
  fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp
  adfs: use timespec64 for time conversion
  kernel/sysctl.c: fix typos in comments
  drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md
  fork: don't copy inconsistent signal handler state to child
  signal: make get_signal() return bool
  signal: make sigkill_pending() return bool
  ...

5 files changed, 41 insertions, 5 deletions

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 1746131bc9cb..184193bcb262 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1072,6 +1072,24 @@ PAGE_SIZE multiple when read back.
 	high limit is used and monitored properly, this limit's
 	utility is limited to providing the final safety net.
 
+  memory.oom.group
+	A read-write single value file which exists on non-root
+	cgroups.  The default value is "0".
+
+	Determines whether the cgroup should be treated as
+	an indivisible workload by the OOM killer. If set,
+	all tasks belonging to the cgroup or to its descendants
+	(if the memory cgroup is not a leaf cgroup) are killed
+	together or not at all. This can be used to avoid
+	partial kills to guarantee workload integrity.
+
+	Tasks with the OOM protection (oom_score_adj set to -1000)
+	are treated as an exception and are never killed.
+
+	If the OOM killer is invoked in a cgroup, it's not going
+	to kill any tasks outside of this cgroup, regardless
+	memory.oom.group values of ancestor cgroups.
+
   memory.events
 	A read-only flat-keyed file which exists on non-root cgroups.
 	The following entries are defined.  Unless specified
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bffb0caa3693..970d837bd57f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3041,8 +3041,9 @@
 			on: enable the feature
 
 	page_poison=	[KNL] Boot-time parameter changing the state of
-			poisoning on the buddy allocator.
-			off: turn off poisoning
+			poisoning on the buddy allocator, available with
+			CONFIG_PAGE_POISONING=y.
+			off: turn off poisoning (default)
 			on: turn on poisoning
 
 	panic=		[KNL] Kernel behaviour on panic: delay <timeout>
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 1605acbb23b6..22b4b00dee31 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -870,6 +870,7 @@ Committed_AS:   100056 kB
 VmallocTotal:   112216 kB
 VmallocUsed:       428 kB
 VmallocChunk:   111088 kB
+Percpu:          62080 kB
 HardwareCorrupted:   0 kB
 AnonHugePages:   49152 kB
 ShmemHugePages:      0 kB
@@ -962,6 +963,8 @@ Committed_AS: The amount of memory presently allocated on the system.
 VmallocTotal: total size of vmalloc memory area
  VmallocUsed: amount of vmalloc area which is used
 VmallocChunk: largest contiguous block of vmalloc area which is free
+      Percpu: Memory allocated to the percpu allocator used to back percpu
+              allocations. This stat excludes the cost of metadata.
 
 ..............................................................................
 
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 59585030cbaf..37a679501ddc 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -38,6 +38,7 @@ show up in /proc/sys/kernel:
 - hung_task_panic
 - hung_task_check_count
 - hung_task_timeout_secs
+- hung_task_check_interval_secs
 - hung_task_warnings
 - hyperv_record_panic_msg
 - kexec_load_disabled
@@ -355,7 +356,7 @@ This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
 
 hung_task_timeout_secs:
 
-Check interval. When a task in D state did not get scheduled
+When a task in D state did not get scheduled
 for more than this value report a warning.
 This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
 
@@ -364,6 +365,18 @@ Possible values to set are in range {0..LONG_MAX/HZ}.
 
 ==============================================================
 
+hung_task_check_interval_secs:
+
+Hung task check interval. If hung task checking is enabled
+(see hung_task_timeout_secs), the check is done every
+hung_task_check_interval_secs seconds.
+This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
+
+0 (default): means use hung_task_timeout_secs as checking interval.
+Possible values to set are in range {0..LONG_MAX/HZ}.
+
+==============================================================
+
 hung_task_warnings:
 
 The maximum number of warnings to report. During a check interval
@@ -451,7 +464,8 @@ Notes:
 1) kernel doesn't guarantee, that new object will have desired id. So,
 it's up to userspace, how to handle an object with "wrong" id.
 2) Toggle with non-default value will be set back to -1 by kernel after
-successful IPC object allocation.
+successful IPC object allocation. If an IPC object allocation syscall
+fails, it is undefined if the value remains unmodified or is reset to -1.
 
 ==============================================================
 
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index e72853b6d725..7d73882e2c27 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -691,7 +691,7 @@ and don't use much of it.
 The default value is 0.
 
 See Documentation/vm/overcommit-accounting.rst and
-mm/mmap.c::__vm_enough_memory() for more information.
+mm/util.c::__vm_enough_memory() for more information.
 
 ==============================================================