Commit af7175bc authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Jonathan Corbet

flexible-arrays.txt: standardize document format

Each text file under Documentation follows a different
format. Some doesn't even have titles!

Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx:

- use :Author: and :Updated: markups;
- use proper markup for the document title;
- mark the literal-blocks.
Signed-off-by: 's avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: 's avatarJonathan Corbet <corbet@lwn.net>
parent 72fd15c0
===================================
Using flexible arrays in the kernel
Last updated for 2.6.32
Jonathan Corbet <corbet@lwn.net>
===================================
:Updated: Last updated for 2.6.32
:Author: Jonathan Corbet <corbet@lwn.net>
Large contiguous memory allocations can be unreliable in the Linux kernel.
Kernel programmers will sometimes respond to this problem by allocating
......@@ -26,7 +29,7 @@ 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:
The creation of a flexible array is done with::
#include <linux/flex_array.h>
......@@ -40,14 +43,14 @@ 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:
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:
Storing data into a flexible array is accomplished with a call to::
int flex_array_put(struct flex_array *array, unsigned int element_nr,
void *src, gfp_t flags);
......@@ -63,7 +66,7 @@ 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:
entering atomic context, using::
int flex_array_prealloc(struct flex_array *array, unsigned int start,
unsigned int nr_elements, gfp_t flags);
......@@ -73,7 +76,7 @@ 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:
Getting data back out of the array is done with::
void *flex_array_get(struct flex_array *fa, unsigned int element_nr);
......@@ -89,7 +92,7 @@ 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:
Individual elements in the array can be cleared with::
int flex_array_clear(struct flex_array *array, unsigned int element_nr);
......@@ -97,7 +100,7 @@ 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:
allocated size of an array, call::
int flex_array_shrink(struct flex_array *array);
......@@ -106,12 +109,12 @@ 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:
It is possible to remove all elements of an array with a call to::
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:
Freeing the entire array is done with::
void flex_array_free(struct flex_array *array);
......
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