Merge tag 'v5.2-rc5' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

5 files changed, 58 insertions, 110 deletions

diff --git a/Documentation/arm64/sve.txt b/Documentation/arm64/sve.txt
index 9940e924a47e..5689fc9a976a 100644
--- a/Documentation/arm64/sve.txt
+++ b/Documentation/arm64/sve.txt
@@ -56,6 +56,18 @@ model features for SVE is included in Appendix A.
   is to connect to a target process first and then attempt a
   ptrace(PTRACE_GETREGSET, pid, NT_ARM_SVE, &iov).
 
+* Whenever SVE scalable register values (Zn, Pn, FFR) are exchanged in memory
+  between userspace and the kernel, the register value is encoded in memory in
+  an endianness-invariant layout, with bits [(8 * i + 7) : (8 * i)] encoded at
+  byte offset i from the start of the memory representation.  This affects for
+  example the signal frame (struct sve_context) and ptrace interface
+  (struct user_sve_header) and associated data.
+
+  Beware that on big-endian systems this results in a different byte order than
+  for the FPSIMD V-registers, which are stored as single host-endian 128-bit
+  values, with bits [(127 - 8 * i) : (120 - 8 * i)] of the register encoded at
+  byte offset i.  (struct fpsimd_context, struct user_fpsimd_state).
+
 
 2.  Vector length terminology
 -----------------------------
@@ -124,6 +136,10 @@ the SVE instruction set architecture.
   size and layout.  Macros SVE_SIG_* are defined [1] to facilitate access to
   the members.
 
+* Each scalable register (Zn, Pn, FFR) is stored in an endianness-invariant
+  layout, with bits [(8 * i + 7) : (8 * i)] stored at byte offset i from the
+  start of the register's representation in memory.
+
 * If the SVE context is too big to fit in sigcontext.__reserved[], then extra
   space is allocated on the stack, an extra_context record is written in
   __reserved[] referencing this space.  sve_context is then written in the
diff --git a/Documentation/block/switching-sched.txt b/Documentation/block/switching-sched.txt
index 3b2612e342f1..7977f6fb8b20 100644
--- a/Documentation/block/switching-sched.txt
+++ b/Documentation/block/switching-sched.txt
@@ -13,11 +13,9 @@ you can do so by typing:
 
 # mount none /sys -t sysfs
 
-As of the Linux 2.6.10 kernel, it is now possible to change the
-IO scheduler for a given block device on the fly (thus making it possible,
-for instance, to set the CFQ scheduler for the system default, but
-set a specific device to use the deadline or noop schedulers - which
-can improve that device's throughput).
+It is possible to change the IO scheduler for a given block device on
+the fly to select one of mq-deadline, none, bfq, or kyber schedulers -
+which can improve that device's throughput.
 
 To set a specific scheduler, simply do this:
 
@@ -30,8 +28,8 @@ The list of defined schedulers can be found by simply doing
 a "cat /sys/block/DEV/queue/scheduler" - the list of valid names
 will be displayed, with the currently selected scheduler in brackets:
 
-# cat /sys/block/hda/queue/scheduler
-noop deadline [cfq]
-# echo deadline > /sys/block/hda/queue/scheduler
-# cat /sys/block/hda/queue/scheduler
-noop [deadline] cfq
+# cat /sys/block/sda/queue/scheduler
+[mq-deadline] kyber bfq none
+# echo none >/sys/block/sda/queue/scheduler
+# cat /sys/block/sda/queue/scheduler
+[none] mq-deadline kyber bfq
diff --git a/Documentation/cgroup-v1/blkio-controller.txt b/Documentation/cgroup-v1/blkio-controller.txt
index 673dc34d3f78..d1a1b7bdd03a 100644
--- a/Documentation/cgroup-v1/blkio-controller.txt
+++ b/Documentation/cgroup-v1/blkio-controller.txt
@@ -8,61 +8,13 @@ both at leaf nodes as well as at intermediate nodes in a storage hierarchy.
 Plan is to use the same cgroup based management interface for blkio controller
 and based on user options switch IO policies in the background.
 
-Currently two IO control policies are implemented. First one is proportional
-weight time based division of disk policy. It is implemented in CFQ. Hence
-this policy takes effect only on leaf nodes when CFQ is being used. The second
-one is throttling policy which can be used to specify upper IO rate limits
-on devices. This policy is implemented in generic block layer and can be
-used on leaf nodes as well as higher level logical devices like device mapper.
+One IO control policy is throttling policy which can be used to
+specify upper IO rate limits on devices. This policy is implemented in
+generic block layer and can be used on leaf nodes as well as higher
+level logical devices like device mapper.
 
 HOWTO
 =====
-Proportional Weight division of bandwidth
------------------------------------------
-You can do a very simple testing of running two dd threads in two different
-cgroups. Here is what you can do.
-
-- Enable Block IO controller
-	CONFIG_BLK_CGROUP=y
-
-- Enable group scheduling in CFQ
-	CONFIG_CFQ_GROUP_IOSCHED=y
-
-- Compile and boot into kernel and mount IO controller (blkio); see
-  cgroups.txt, Why are cgroups needed?.
-
-	mount -t tmpfs cgroup_root /sys/fs/cgroup
-	mkdir /sys/fs/cgroup/blkio
-	mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
-
-- Create two cgroups
-	mkdir -p /sys/fs/cgroup/blkio/test1/ /sys/fs/cgroup/blkio/test2
-
-- Set weights of group test1 and test2
-	echo 1000 > /sys/fs/cgroup/blkio/test1/blkio.weight
-	echo 500 > /sys/fs/cgroup/blkio/test2/blkio.weight
-
-- Create two same size files (say 512MB each) on same disk (file1, file2) and
-  launch two dd threads in different cgroup to read those files.
-
-	sync
-	echo 3 > /proc/sys/vm/drop_caches
-
-	dd if=/mnt/sdb/zerofile1 of=/dev/null &
-	echo $! > /sys/fs/cgroup/blkio/test1/tasks
-	cat /sys/fs/cgroup/blkio/test1/tasks
-
-	dd if=/mnt/sdb/zerofile2 of=/dev/null &
-	echo $! > /sys/fs/cgroup/blkio/test2/tasks
-	cat /sys/fs/cgroup/blkio/test2/tasks
-
-- At macro level, first dd should finish first. To get more precise data, keep
-  on looking at (with the help of script), at blkio.disk_time and
-  blkio.disk_sectors files of both test1 and test2 groups. This will tell how
-  much disk time (in milliseconds), each group got and how many sectors each
-  group dispatched to the disk. We provide fairness in terms of disk time, so
-  ideally io.disk_time of cgroups should be in proportion to the weight.
-
 Throttling/Upper Limit policy
 -----------------------------
 - Enable Block IO controller
@@ -94,7 +46,7 @@ Throttling/Upper Limit policy
 Hierarchical Cgroups
 ====================
 
-Both CFQ and throttling implement hierarchy support; however,
+Throttling implements hierarchy support; however,
 throttling's hierarchy support is enabled iff "sane_behavior" is
 enabled from cgroup side, which currently is a development option and
 not publicly available.
@@ -107,9 +59,8 @@ If somebody created a hierarchy like as follows.
 			|
 		     test3
 
-CFQ by default and throttling with "sane_behavior" will handle the
-hierarchy correctly.  For details on CFQ hierarchy support, refer to
-Documentation/block/cfq-iosched.txt.  For throttling, all limits apply
+Throttling with "sane_behavior" will handle the
+hierarchy correctly. For throttling, all limits apply
 to the whole subtree while all statistics are local to the IOs
 directly generated by tasks in that cgroup.
 
@@ -130,10 +81,6 @@ CONFIG_DEBUG_BLK_CGROUP
 	- Debug help. Right now some additional stats file show up in cgroup
 	  if this option is enabled.
 
-CONFIG_CFQ_GROUP_IOSCHED
-	- Enables group scheduling in CFQ. Currently only 1 level of group
-	  creation is allowed.
-
 CONFIG_BLK_DEV_THROTTLING
 	- Enable block device throttling support in block layer.
 
@@ -344,32 +291,3 @@ Common files among various policies
 - blkio.reset_stats
 	- Writing an int to this file will result in resetting all the stats
 	  for that cgroup.
-
-CFQ sysfs tunable
-=================
-/sys/block/<disk>/queue/iosched/slice_idle
-------------------------------------------
-On a faster hardware CFQ can be slow, especially with sequential workload.
-This happens because CFQ idles on a single queue and single queue might not
-drive deeper request queue depths to keep the storage busy. In such scenarios
-one can try setting slice_idle=0 and that would switch CFQ to IOPS
-(IO operations per second) mode on NCQ supporting hardware.
-
-That means CFQ will not idle between cfq queues of a cfq group and hence be
-able to driver higher queue depth and achieve better throughput. That also
-means that cfq provides fairness among groups in terms of IOPS and not in
-terms of disk time.
-
-/sys/block/<disk>/queue/iosched/group_idle
-------------------------------------------
-If one disables idling on individual cfq queues and cfq service trees by
-setting slice_idle=0, group_idle kicks in. That means CFQ will still idle
-on the group in an attempt to provide fairness among groups.
-
-By default group_idle is same as slice_idle and does not do anything if
-slice_idle is enabled.
-
-One can experience an overall throughput drop if you have created multiple
-groups and put applications in that group which are not driving enough
-IO to keep disk busy. In that case set group_idle=0, and CFQ will not idle
-on individual groups and throughput should improve.
diff --git a/Documentation/cgroup-v1/hugetlb.txt b/Documentation/cgroup-v1/hugetlb.txt
index 106245c3aecc..1260e5369b9b 100644
--- a/Documentation/cgroup-v1/hugetlb.txt
+++ b/Documentation/cgroup-v1/hugetlb.txt
@@ -32,14 +32,18 @@ Brief summary of control files
  hugetlb.<hugepagesize>.usage_in_bytes     # show current usage for "hugepagesize" hugetlb
  hugetlb.<hugepagesize>.failcnt		   # show the number of allocation failure due to HugeTLB limit
 
-For a system supporting two hugepage size (16M and 16G) the control
+For a system supporting three hugepage sizes (64k, 32M and 1G), the control
 files include:
 
-hugetlb.16GB.limit_in_bytes
-hugetlb.16GB.max_usage_in_bytes
-hugetlb.16GB.usage_in_bytes
-hugetlb.16GB.failcnt
-hugetlb.16MB.limit_in_bytes
-hugetlb.16MB.max_usage_in_bytes
-hugetlb.16MB.usage_in_bytes
-hugetlb.16MB.failcnt
+hugetlb.1GB.limit_in_bytes
+hugetlb.1GB.max_usage_in_bytes
+hugetlb.1GB.usage_in_bytes
+hugetlb.1GB.failcnt
+hugetlb.64KB.limit_in_bytes
+hugetlb.64KB.max_usage_in_bytes
+hugetlb.64KB.usage_in_bytes
+hugetlb.64KB.failcnt
+hugetlb.32MB.limit_in_bytes
+hugetlb.32MB.max_usage_in_bytes
+hugetlb.32MB.usage_in_bytes
+hugetlb.32MB.failcnt
diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt
index eef7d9d259e8..1da2f1668f08 100644
--- a/Documentation/filesystems/overlayfs.txt
+++ b/Documentation/filesystems/overlayfs.txt
@@ -336,8 +336,20 @@ the copied layers will fail the verification of the lower root file handle.
 Non-standard behavior
 ---------------------
 
-Overlayfs can now act as a POSIX compliant filesystem with the following
-features turned on:
+Current version of overlayfs can act as a mostly POSIX compliant
+filesystem.
+
+This is the list of cases that overlayfs doesn't currently handle:
+
+a) POSIX mandates updating st_atime for reads.  This is currently not
+done in the case when the file resides on a lower layer.
+
+b) If a file residing on a lower layer is opened for read-only and then
+memory mapped with MAP_SHARED, then subsequent changes to the file are not
+reflected in the memory mapping.
+
+The following options allow overlayfs to act more like a standards
+compliant filesystem:
 
 1) "redirect_dir"