Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few misc things

 - the rest of MM

-  remove flex_arrays, replace with new simple radix-tree implementation

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (38 commits)
  Drop flex_arrays
  sctp: convert to genradix
  proc: commit to genradix
  generic radix trees
  selinux: convert to kvmalloc
  md: convert to kvmalloc
  openvswitch: convert to kvmalloc
  of: fix kmemleak crash caused by imbalance in early memory reservation
  mm: memblock: update comments and kernel-doc
  memblock: split checks whether a region should be skipped to a helper function
  memblock: remove memblock_{set,clear}_region_flags
  memblock: drop memblock_alloc_*_nopanic() variants
  memblock: memblock_alloc_try_nid: don't panic
  treewide: add checks for the return value of memblock_alloc*()
  swiotlb: add checks for the return value of memblock_alloc*()
  init/main: add checks for the return value of memblock_alloc*()
  mm/percpu: add checks for the return value of memblock_alloc*()
  sparc: add checks for the return value of memblock_alloc*()
  ia64: add checks for the return value of memblock_alloc*()
  arch: don't memset(0) memory returned by memblock_alloc()
  ...

Documentation/core-api/flexible-arrays.rst

@@ -1,130 +0,0 @@
-
-===================================
-Using flexible arrays in the kernel
-===================================
-
-Large contiguous memory allocations can be unreliable in the Linux kernel.
-Kernel programmers will sometimes respond to this problem by allocating
-pages with :c:func:`vmalloc()`.  This solution not ideal, though.  On 32-bit
-systems, memory from vmalloc() must be mapped into a relatively small address
-space; it's easy to run out.  On SMP systems, the page table changes required
-by vmalloc() allocations can require expensive cross-processor interrupts on
-all CPUs.  And, on all systems, use of space in the vmalloc() range increases
-pressure on the translation lookaside buffer (TLB), reducing the performance
-of the system.
-
-In many cases, the need for memory from vmalloc() can be eliminated by piecing
-together an array from smaller parts; the flexible array library exists to make
-this task easier.
-
-A flexible array holds an arbitrary (within limits) number of fixed-sized
-objects, accessed via an integer index.  Sparse arrays are handled
-reasonably well.  Only single-page allocations are made, so memory
-allocation failures should be relatively rare.  The down sides are that the
-arrays cannot be indexed directly, individual object size cannot exceed the
-system page size, and putting data into a flexible array requires a copy
-operation.  It's also worth noting that flexible arrays do no internal
-locking at all; if concurrent access to an array is possible, then the
-caller must arrange for appropriate mutual exclusion.
-
-The creation of a flexible array is done with :c:func:`flex_array_alloc()`::
-
-    #include <linux/flex_array.h>
-
-    struct flex_array *flex_array_alloc(int element_size,
-					unsigned int total,
-					gfp_t flags);
-
-The individual object size is provided by ``element_size``, while total is the
-maximum number of objects which can be stored in the array.  The flags
-argument is passed directly to the internal memory allocation calls.  With
-the current code, using flags to ask for high memory is likely to lead to
-notably unpleasant side effects.
-
-It is also possible to define flexible arrays at compile time with::
-
-    DEFINE_FLEX_ARRAY(name, element_size, total);
-
-This macro will result in a definition of an array with the given name; the
-element size and total will be checked for validity at compile time.
-
-Storing data into a flexible array is accomplished with a call to
-:c:func:`flex_array_put()`::
-
-    int flex_array_put(struct flex_array *array, unsigned int element_nr,
-    		       void *src, gfp_t flags);
-
-This call will copy the data from src into the array, in the position
-indicated by ``element_nr`` (which must be less than the maximum specified when
-the array was created).  If any memory allocations must be performed, flags
-will be used.  The return value is zero on success, a negative error code
-otherwise.
-
-There might possibly be a need to store data into a flexible array while
-running in some sort of atomic context; in this situation, sleeping in the
-memory allocator would be a bad thing.  That can be avoided by using
-``GFP_ATOMIC`` for the flags value, but, often, there is a better way.  The
-trick is to ensure that any needed memory allocations are done before
-entering atomic context, using :c:func:`flex_array_prealloc()`::
-
-    int flex_array_prealloc(struct flex_array *array, unsigned int start,
-			    unsigned int nr_elements, gfp_t flags);
-
-This function will ensure that memory for the elements indexed in the range
-defined by ``start`` and ``nr_elements`` has been allocated.  Thereafter, a
-``flex_array_put()`` call on an element in that range is guaranteed not to
-block.
-
-Getting data back out of the array is done with :c:func:`flex_array_get()`::
-
-    void *flex_array_get(struct flex_array *fa, unsigned int element_nr);
-
-The return value is a pointer to the data element, or NULL if that
-particular element has never been allocated.
-
-Note that it is possible to get back a valid pointer for an element which
-has never been stored in the array.  Memory for array elements is allocated
-one page at a time; a single allocation could provide memory for several
-adjacent elements.  Flexible array elements are normally initialized to the
-value ``FLEX_ARRAY_FREE`` (defined as 0x6c in <linux/poison.h>), so errors
-involving that number probably result from use of unstored array entries.
-Note that, if array elements are allocated with ``__GFP_ZERO``, they will be
-initialized to zero and this poisoning will not happen.
-
-Individual elements in the array can be cleared with
-:c:func:`flex_array_clear()`::
-
-    int flex_array_clear(struct flex_array *array, unsigned int element_nr);
-
-This function will set the given element to ``FLEX_ARRAY_FREE`` and return
-zero.  If storage for the indicated element is not allocated for the array,
-``flex_array_clear()`` will return ``-EINVAL`` instead.  Note that clearing an
-element does not release the storage associated with it; to reduce the
-allocated size of an array, call :c:func:`flex_array_shrink()`::
-
-    int flex_array_shrink(struct flex_array *array);
-
-The return value will be the number of pages of memory actually freed.
-This function works by scanning the array for pages containing nothing but
-``FLEX_ARRAY_FREE`` bytes, so (1) it can be expensive, and (2) it will not work
-if the array's pages are allocated with ``__GFP_ZERO``.
-
-It is possible to remove all elements of an array with a call to
-:c:func:`flex_array_free_parts()`::
-
-    void flex_array_free_parts(struct flex_array *array);
-
-This call frees all elements, but leaves the array itself in place.
-Freeing the entire array is done with :c:func:`flex_array_free()`::
-
-    void flex_array_free(struct flex_array *array);
-
-As of this writing, there are no users of flexible arrays in the mainline
-kernel.  The functions described here are also not exported to modules;
-that will probably be fixed when somebody comes up with a need for it.
-
-
-Flexible array functions
-------------------------
-
-.. kernel-doc:: include/linux/flex_array.h

Documentation/core-api/generic-radix-tree.rst

@@ -0,0 +1,12 @@
+=================================
+Generic radix trees/sparse arrays
+=================================
+
+.. kernel-doc:: include/linux/generic-radix-tree.h
+   :doc: Generic radix trees/sparse arrays
+
+generic radix tree functions
+----------------------------
+
+.. kernel-doc:: include/linux/generic-radix-tree.h
+   :functions:

Documentation/core-api/index.rst

@@ -28,6 +28,7 @@ Core utilities
    errseq
    printk-formats
    circular-buffers
+   generic-radix-tree
    memory-allocation
    mm-api
    gfp_mask-from-fs-io