Merge branch 'akpm' (more incoming from Andrew)

Merge second patch-bomb from Andrew Morton:

 - A little DM fix

 - the MM queue

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (154 commits)
  ksm: allocate roots when needed
  mm: cleanup "swapcache" in do_swap_page
  mm,ksm: swapoff might need to copy
  mm,ksm: FOLL_MIGRATION do migration_entry_wait
  ksm: shrink 32-bit rmap_item back to 32 bytes
  ksm: treat unstable nid like in stable tree
  ksm: add some comments
  tmpfs: fix mempolicy object leaks
  tmpfs: fix use-after-free of mempolicy object
  mm/fadvise.c: drain all pagevecs if POSIX_FADV_DONTNEED fails to discard all pages
  mm: export mmu notifier invalidates
  mm: accelerate mm_populate() treatment of THP pages
  mm: use long type for page counts in mm_populate() and get_user_pages()
  mm: accurately document nr_free_*_pages functions with code comments
  HWPOISON: change order of error_states[]'s elements
  HWPOISON: fix misjudgement of page_action() for errors on mlocked pages
  memcg: stop warning on memcg_propagate_kmem
  net: change type of virtio_chan->p9_max_pages
  vmscan: change type of vm_total_pages to unsigned long
  fs/nfsd: change type of max_delegations, nfsd_drc_max_mem and nfsd_drc_mem_used
  ...

3 files changed, 103 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-ksm b/Documentation/ABI/testing/sysfs-kernel-mm-ksm
new file mode 100644
index 000000000000..73e653ee2481
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-ksm
@@ -0,0 +1,52 @@
+What:           /sys/kernel/mm/ksm
+Date:           September 2009
+KernelVersion:  2.6.32
+Contact:        Linux memory management mailing list <linux-mm@kvack.org>
+Description:    Interface for Kernel Samepage Merging (KSM)
+
+What:           /sys/kernel/mm/ksm/full_scans
+What:           /sys/kernel/mm/ksm/pages_shared
+What:           /sys/kernel/mm/ksm/pages_sharing
+What:           /sys/kernel/mm/ksm/pages_to_scan
+What:           /sys/kernel/mm/ksm/pages_unshared
+What:           /sys/kernel/mm/ksm/pages_volatile
+What:           /sys/kernel/mm/ksm/run
+What:           /sys/kernel/mm/ksm/sleep_millisecs
+Date:           September 2009
+Contact:        Linux memory management mailing list <linux-mm@kvack.org>
+Description:    Kernel Samepage Merging daemon sysfs interface
+
+                full_scans: how many times all mergeable areas have been
+                scanned.
+
+                pages_shared: how many shared pages are being used.
+
+                pages_sharing: how many more sites are sharing them i.e. how
+                much saved.
+
+                pages_to_scan: how many present pages to scan before ksmd goes
+                to sleep.
+
+                pages_unshared: how many pages unique but repeatedly checked
+                for merging.
+
+                pages_volatile: how many pages changing too fast to be placed
+                in a tree.
+
+                run: write 0 to disable ksm, read 0 while ksm is disabled.
+                        write 1 to run ksm, read 1 while ksm is running.
+                        write 2 to disable ksm and unmerge all its pages.
+
+                sleep_millisecs: how many milliseconds ksm should sleep between
+                scans.
+
+                See Documentation/vm/ksm.txt for more information.
+
+What:           /sys/kernel/mm/ksm/merge_across_nodes
+Date:           January 2013
+KernelVersion:  3.9
+Contact:        Linux memory management mailing list <linux-mm@kvack.org>
+Description:    Control merging pages across different NUMA nodes.
+
+                When it is set to 0 only pages from the same node are merged,
+                otherwise pages from all nodes can be merged together (default).
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9aa8ff3e54dc..766087781ecd 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1640,6 +1640,42 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         that the amount of memory usable for all allocations
                         is not too small.
 
+        movablemem_map=acpi
+                        [KNL,X86,IA-64,PPC] This parameter is similar to
+                        memmap except it specifies the memory map of
+                        ZONE_MOVABLE.
+                        This option inform the kernel to use Hot Pluggable bit
+                        in flags from SRAT from ACPI BIOS to determine which
+                        memory devices could be hotplugged. The corresponding
+                        memory ranges will be set as ZONE_MOVABLE.
+                        NOTE: Whatever node the kernel resides in will always
+                              be un-hotpluggable.
+
+        movablemem_map=nn[KMG]@ss[KMG]
+                        [KNL,X86,IA-64,PPC] This parameter is similar to
+                        memmap except it specifies the memory map of
+                        ZONE_MOVABLE.
+                        If user specifies memory ranges, the info in SRAT will
+                        be ingored. And it works like the following:
+                        - If more ranges are all within one node, then from
+                          lowest ss to the end of the node will be ZONE_MOVABLE.
+                        - If a range is within a node, then from ss to the end
+                          of the node will be ZONE_MOVABLE.
+                        - If a range covers two or more nodes, then from ss to
+                          the end of the 1st node will be ZONE_MOVABLE, and all
+                          the rest nodes will only have ZONE_MOVABLE.
+                        If memmap is specified at the same time, the
+                        movablemem_map will be limited within the memmap
+                        areas. If kernelcore or movablecore is also specified,
+                        movablemem_map will have higher priority to be
+                        satisfied. So the administrator should be careful that
+                        the amount of movablemem_map areas are not too large.
+                        Otherwise kernel won't have enough memory to start.
+                        NOTE: We don't stop users specifying the node the
+                              kernel resides in as hotpluggable so that this
+                              option can be used as a workaround of firmware
+                              bugs.
+
         MTD_Partition=  [MTD]
                         Format: <name>,<region-number>,<size>,<offset>
 
diff --git a/Documentation/vm/ksm.txt b/Documentation/vm/ksm.txt
index b392e496f816..f34a8ee6f860 100644
--- a/Documentation/vm/ksm.txt
+++ b/Documentation/vm/ksm.txt
@@ -58,6 +58,21 @@ sleep_millisecs  - how many milliseconds ksmd should sleep before next scan
                    e.g. "echo 20 > /sys/kernel/mm/ksm/sleep_millisecs"
                    Default: 20 (chosen for demonstration purposes)
 
+merge_across_nodes - specifies if pages from different numa nodes can be merged.
+                   When set to 0, ksm merges only pages which physically
+                   reside in the memory area of same NUMA node. That brings
+                   lower latency to access of shared pages. Systems with more
+                   nodes, at significant NUMA distances, are likely to benefit
+                   from the lower latency of setting 0. Smaller systems, which
+                   need to minimize memory usage, are likely to benefit from
+                   the greater sharing of setting 1 (default). You may wish to
+                   compare how your system performs under each setting, before
+                   deciding on which to use. merge_across_nodes setting can be
+                   changed only when there are no ksm shared pages in system:
+                   set run 2 to unmerge pages first, then to 1 after changing
+                   merge_across_nodes, to remerge according to the new setting.
+                   Default: 1 (merging across nodes as in earlier releases)
+
 run              - set 0 to stop ksmd from running but keep merged pages,
                    set 1 to run ksmd e.g. "echo 1 > /sys/kernel/mm/ksm/run",
                    set 2 to stop ksmd and unmerge all pages currently merged,