Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <[email protected]>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...

Author: torvalds

Documentation/admin-guide/cgroup-v1/hugetlb.rst

@@ -29,12 +29,14 @@ Brief summary of control files::
  hugetlb.<hugepagesize>.max_usage_in_bytes             # show max "hugepagesize" hugetlb  usage recorded
  hugetlb.<hugepagesize>.usage_in_bytes                 # show current usage for "hugepagesize" hugetlb
  hugetlb.<hugepagesize>.failcnt                        # show the number of allocation failure due to HugeTLB usage limit
+ hugetlb.<hugepagesize>.numa_stat                      # show the numa information of the hugetlb memory charged to this cgroup
 
 For a system supporting three hugepage sizes (64k, 32M and 1G), the control
 files include::
 
   hugetlb.1GB.limit_in_bytes
   hugetlb.1GB.max_usage_in_bytes
+  hugetlb.1GB.numa_stat
   hugetlb.1GB.usage_in_bytes
   hugetlb.1GB.failcnt
   hugetlb.1GB.rsvd.limit_in_bytes
@@ -43,6 +45,7 @@ files include::
   hugetlb.1GB.rsvd.failcnt
   hugetlb.64KB.limit_in_bytes
   hugetlb.64KB.max_usage_in_bytes
+  hugetlb.64KB.numa_stat
   hugetlb.64KB.usage_in_bytes
   hugetlb.64KB.failcnt
   hugetlb.64KB.rsvd.limit_in_bytes
@@ -51,6 +54,7 @@ files include::
   hugetlb.64KB.rsvd.failcnt
   hugetlb.32MB.limit_in_bytes
   hugetlb.32MB.max_usage_in_bytes
+  hugetlb.32MB.numa_stat
   hugetlb.32MB.usage_in_bytes
   hugetlb.32MB.failcnt
   hugetlb.32MB.rsvd.limit_in_bytes

Documentation/admin-guide/cgroup-v2.rst

@@ -1268,6 +1268,9 @@ PAGE_SIZE multiple when read back.
 		The number of processes belonging to this cgroup
 		killed by any kind of OOM killer.
 
+          oom_group_kill
+                The number of times a group OOM has occurred.
+
   memory.events.local
 	Similar to memory.events but the fields in the file are local
 	to the cgroup i.e. not hierarchical. The file modified event
@@ -1311,6 +1314,9 @@ PAGE_SIZE multiple when read back.
 	  sock (npn)
 		Amount of memory used in network transmission buffers
 
+	  vmalloc (npn)
+		Amount of memory used for vmap backed memory.
+
 	  shmem
 		Amount of cached filesystem data that is swap-backed,
 		such as tmpfs, shm segments, shared anonymous mmap()s
@@ -2260,6 +2266,11 @@ HugeTLB Interface Files
 	are local to the cgroup i.e. not hierarchical. The file modified event
 	generated on this file reflects only the local events.
 
+  hugetlb.<hugepagesize>.numa_stat
+	Similar to memory.numa_stat, it shows the numa information of the
+        hugetlb pages of <hugepagesize> in this cgroup.  Only active in
+        use hugetlb pages are included.  The per-node values are in bytes.
+
 Misc
 ----
 

Documentation/admin-guide/mm/damon/reclaim.rst

@@ -208,6 +208,31 @@ PID of the DAMON thread.
 If DAMON_RECLAIM is enabled, this becomes the PID of the worker thread.  Else,
 -1.
 
+nr_reclaim_tried_regions
+------------------------
+
+Number of memory regions that tried to be reclaimed by DAMON_RECLAIM.
+
+bytes_reclaim_tried_regions
+---------------------------
+
+Total bytes of memory regions that tried to be reclaimed by DAMON_RECLAIM.
+
+nr_reclaimed_regions
+--------------------
+
+Number of memory regions that successfully be reclaimed by DAMON_RECLAIM.
+
+bytes_reclaimed_regions
+-----------------------
+
+Total bytes of memory regions that successfully be reclaimed by DAMON_RECLAIM.
+
+nr_quota_exceeds
+----------------
+
+Number of times that the time/space quota limits have exceeded.
+
 Example
 =======
 

Documentation/admin-guide/mm/damon/usage.rst

@@ -7,37 +7,40 @@ Detailed Usages
 DAMON provides below three interfaces for different users.
 
 - *DAMON user space tool.*
-  This is for privileged people such as system administrators who want a
-  just-working human-friendly interface.  Using this, users can use the DAMON’s
-  major features in a human-friendly way.  It may not be highly tuned for
-  special cases, though.  It supports both virtual and physical address spaces
-  monitoring.
+  `This <https://github.com/awslabs/damo>`_ is for privileged people such as
+  system administrators who want a just-working human-friendly interface.
+  Using this, users can use the DAMON’s major features in a human-friendly way.
+  It may not be highly tuned for special cases, though.  It supports both
+  virtual and physical address spaces monitoring.  For more detail, please
+  refer to its `usage document
+  <https://github.com/awslabs/damo/blob/next/USAGE.md>`_.
 - *debugfs interface.*
-  This is for privileged user space programmers who want more optimized use of
-  DAMON.  Using this, users can use DAMON’s major features by reading
-  from and writing to special debugfs files.  Therefore, you can write and use
-  your personalized DAMON debugfs wrapper programs that reads/writes the
-  debugfs files instead of you.  The DAMON user space tool is also a reference
-  implementation of such programs.  It supports both virtual and physical
-  address spaces monitoring.
+  :ref:`This <debugfs_interface>` is for privileged user space programmers who
+  want more optimized use of DAMON.  Using this, users can use DAMON’s major
+  features by reading from and writing to special debugfs files.  Therefore,
+  you can write and use your personalized DAMON debugfs wrapper programs that
+  reads/writes the debugfs files instead of you.  The `DAMON user space tool
+  <https://github.com/awslabs/damo>`_ is one example of such programs.  It
+  supports both virtual and physical address spaces monitoring.  Note that this
+  interface provides only simple :ref:`statistics <damos_stats>` for the
+  monitoring results.  For detailed monitoring results, DAMON provides a
+  :ref:`tracepoint <tracepoint>`.
 - *Kernel Space Programming Interface.*
-  This is for kernel space programmers.  Using this, users can utilize every
-  feature of DAMON most flexibly and efficiently by writing kernel space
-  DAMON application programs for you.  You can even extend DAMON for various
-  address spaces.
+  :doc:`This </vm/damon/api>` is for kernel space programmers.  Using this,
+  users can utilize every feature of DAMON most flexibly and efficiently by
+  writing kernel space DAMON application programs for you.  You can even extend
+  DAMON for various address spaces.  For detail, please refer to the interface
+  :doc:`document </vm/damon/api>`.
 
-Nevertheless, you could write your own user space tool using the debugfs
-interface.  A reference implementation is available at
-https://github.com/awslabs/damo.  If you are a kernel programmer, you could
-refer to :doc:`/vm/damon/api` for the kernel space programming interface.  For
-the reason, this document describes only the debugfs interface
+
+.. _debugfs_interface:
 
 debugfs Interface
 =================
 
-DAMON exports five files, ``attrs``, ``target_ids``, ``init_regions``,
-``schemes`` and ``monitor_on`` under its debugfs directory,
-``<debugfs>/damon/``.
+DAMON exports eight files, ``attrs``, ``target_ids``, ``init_regions``,
+``schemes``, ``monitor_on``, ``kdamond_pid``, ``mk_contexts`` and
+``rm_contexts`` under its debugfs directory, ``<debugfs>/damon/``.
 
 
 Attributes
@@ -131,24 +134,38 @@ Schemes
 
 For usual DAMON-based data access aware memory management optimizations, users
 would simply want the system to apply a memory management action to a memory
-region of a specific size having a specific access frequency for a specific
-time.  DAMON receives such formalized operation schemes from the user and
-applies those to the target processes.  It also counts the total number and
-size of regions that each scheme is applied.  This statistics can be used for
-online analysis or tuning of the schemes.
+region of a specific access pattern.  DAMON receives such formalized operation
+schemes from the user and applies those to the target processes.
 
 Users can get and set the schemes by reading from and writing to ``schemes``
 debugfs file.  Reading the file also shows the statistics of each scheme.  To
-the file, each of the schemes should be represented in each line in below form:
+the file, each of the schemes should be represented in each line in below
+form::
+
+    <target access pattern> <action> <quota> <watermarks>
+
+You can disable schemes by simply writing an empty string to the file.
+
+Target Access Pattern
+~~~~~~~~~~~~~~~~~~~~~
+
+The ``<target access pattern>`` is constructed with three ranges in below
+form::
+
+    min-size max-size min-acc max-acc min-age max-age
 
-    min-size max-size min-acc max-acc min-age max-age action
+Specifically, bytes for the size of regions (``min-size`` and ``max-size``),
+number of monitored accesses per aggregate interval for access frequency
+(``min-acc`` and ``max-acc``), number of aggregate intervals for the age of
+regions (``min-age`` and ``max-age``) are specified.  Note that the ranges are
+closed interval.
 
-Note that the ranges are closed interval.  Bytes for the size of regions
-(``min-size`` and ``max-size``), number of monitored accesses per aggregate
-interval for access frequency (``min-acc`` and ``max-acc``), number of
-aggregate intervals for the age of regions (``min-age`` and ``max-age``), and a
-predefined integer for memory management actions should be used.  The supported
-numbers and their meanings are as below.
+Action
+~~~~~~
+
+The ``<action>`` is a predefined integer for memory management actions, which
+DAMON will apply to the regions having the target access pattern.  The
+supported numbers and their meanings are as below.
 
  - 0: Call ``madvise()`` for the region with ``MADV_WILLNEED``
  - 1: Call ``madvise()`` for the region with ``MADV_COLD``
@@ -157,20 +174,82 @@ numbers and their meanings are as below.
  - 4: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``
  - 5: Do nothing but count the statistics
 
-You can disable schemes by simply writing an empty string to the file.  For
-example, below commands applies a scheme saying "If a memory region of size in
-[4KiB, 8KiB] is showing accesses per aggregate interval in [0, 5] for aggregate
-interval in [10, 20], page out the region", check the entered scheme again, and
-finally remove the scheme. ::
+Quota
+~~~~~
 
-    # cd <debugfs>/damon
-    # echo "4096 8192    0 5    10 20    2" > schemes
-    # cat schemes
-    4096 8192 0 5 10 20 2 0 0
-    # echo > schemes
+Optimal ``target access pattern`` for each ``action`` is workload dependent, so
+not easy to find.  Worse yet, setting a scheme of some action too aggressive
+can cause severe overhead.  To avoid such overhead, users can limit time and
+size quota for the scheme via the ``<quota>`` in below form::
+
+    <ms> <sz> <reset interval> <priority weights>
+
+This makes DAMON to try to use only up to ``<ms>`` milliseconds for applying
+the action to memory regions of the ``target access pattern`` within the
+``<reset interval>`` milliseconds, and to apply the action to only up to
+``<sz>`` bytes of memory regions within the ``<reset interval>``.  Setting both
+``<ms>`` and ``<sz>`` zero disables the quota limits.
+
+When the quota limit is expected to be exceeded, DAMON prioritizes found memory
+regions of the ``target access pattern`` based on their size, access frequency,
+and age.  For personalized prioritization, users can set the weights for the
+three properties in ``<priority weights>`` in below form::
+
+    <size weight> <access frequency weight> <age weight>
+
+Watermarks
+~~~~~~~~~~
+
+Some schemes would need to run based on current value of the system's specific
+metrics like free memory ratio.  For such cases, users can specify watermarks
+for the condition.::
+
+    <metric> <check interval> <high mark> <middle mark> <low mark>
+
+``<metric>`` is a predefined integer for the metric to be checked.  The
+supported numbers and their meanings are as below.
+
+ - 0: Ignore the watermarks
+ - 1: System's free memory rate (per thousand)
+
+The value of the metric is checked every ``<check interval>`` microseconds.
+
+If the value is higher than ``<high mark>`` or lower than ``<low mark>``, the
+scheme is deactivated.  If the value is lower than ``<mid mark>``, the scheme
+is activated.
+
+.. _damos_stats:
+
+Statistics
+~~~~~~~~~~
+
+It also counts the total number and bytes of regions that each scheme is tried
+to be applied, the two numbers for the regions that each scheme is successfully
+applied, and the total number of the quota limit exceeds.  This statistics can
+be used for online analysis or tuning of the schemes.
+
+The statistics can be shown by reading the ``schemes`` file.  Reading the file
+will show each scheme you entered in each line, and the five numbers for the
+statistics will be added at the end of each line.
 
-The last two integers in the 4th line of above example is the total number and
-the total size of the regions that the scheme is applied.
+Example
+~~~~~~~
+
+Below commands applies a scheme saying "If a memory region of size in [4KiB,
+8KiB] is showing accesses per aggregate interval in [0, 5] for aggregate
+interval in [10, 20], page out the region.  For the paging out, use only up to
+10ms per second, and also don't page out more than 1GiB per second.  Under the
+limitation, page out memory regions having longer age first.  Also, check the
+free memory rate of the system every 5 seconds, start the monitoring and paging
+out when the free memory rate becomes lower than 50%, but stop it if the free
+memory rate becomes larger than 60%, or lower than 30%".::
+
+    # cd <debugfs>/damon
+    # scheme="4096 8192  0 5    10 20    2"  # target access pattern and action
+    # scheme+=" 10 $((1024*1024*1024)) 1000" # quotas
+    # scheme+=" 0 0 100"                     # prioritization weights
+    # scheme+=" 1 5000000 600 500 300"       # watermarks
+    # echo "$scheme" > schemes
 
 
 Turning On/Off
@@ -195,6 +274,54 @@ the monitoring is turned on.  If you write to the files while DAMON is running,
 an error code such as ``-EBUSY`` will be returned.
 
 
+Monitoring Thread PID
+---------------------
+
+DAMON does requested monitoring with a kernel thread called ``kdamond``.  You
+can get the pid of the thread by reading the ``kdamond_pid`` file.  When the
+monitoring is turned off, reading the file returns ``none``. ::
+
+    # cd <debugfs>/damon
+    # cat monitor_on
+    off
+    # cat kdamond_pid
+    none
+    # echo on > monitor_on
+    # cat kdamond_pid
+    18594
+
+
+Using Multiple Monitoring Threads
+---------------------------------
+
+One ``kdamond`` thread is created for each monitoring context.  You can create
+and remove monitoring contexts for multiple ``kdamond`` required use case using
+the ``mk_contexts`` and ``rm_contexts`` files.
+
+Writing the name of the new context to the ``mk_contexts`` file creates a
+directory of the name on the DAMON debugfs directory.  The directory will have
+DAMON debugfs files for the context. ::
+
+    # cd <debugfs>/damon
+    # ls foo
+    # ls: cannot access 'foo': No such file or directory
+    # echo foo > mk_contexts
+    # ls foo
+    # attrs  init_regions  kdamond_pid  schemes  target_ids
+
+If the context is not needed anymore, you can remove it and the corresponding
+directory by putting the name of the context to the ``rm_contexts`` file. ::
+
+    # echo foo > rm_contexts
+    # ls foo
+    # ls: cannot access 'foo': No such file or directory
+
+Note that ``mk_contexts``, ``rm_contexts``, and ``monitor_on`` files are in the
+root directory only.
+
+
+.. _tracepoint:
+
 Tracepoint for Monitoring Results
 =================================
 

Documentation/admin-guide/mm/numa_memory_policy.rst

@@ -408,7 +408,7 @@ follows:
 Memory Policy APIs
 ==================
 
-Linux supports 3 system calls for controlling memory policy.  These APIS
+Linux supports 4 system calls for controlling memory policy.  These APIS
 always affect only the calling task, the calling task's address space, or
 some shared object mapped into the calling task's address space.
 
@@ -460,6 +460,20 @@ requested via the 'flags' argument.
 
 See the mbind(2) man page for more details.
 
+Set home node for a Range of Task's Address Spacec::
+
+	long sys_set_mempolicy_home_node(unsigned long start, unsigned long len,
+					 unsigned long home_node,
+					 unsigned long flags);
+
+sys_set_mempolicy_home_node set the home node for a VMA policy present in the
+task's address range. The system call updates the home node only for the existing
+mempolicy range. Other address ranges are ignored. A home node is the NUMA node
+closest to which page allocation will come from. Specifying the home node override
+the default allocation policy to allocate memory close to the local node for an
+executing CPU.
+
+
 Memory Policy Command Line Interface
 ====================================