@@ -30,6 +30,9 @@
#include <linux/types.h>
#include <linux/xarray.h>
+/* Keep unconverted code working */
+#define radix_tree_root xarray
+
/*
* The bottom two bits of the slot determine how the remaining bits in the
* slot are interpreted:
@@ -59,10 +62,7 @@ static inline bool radix_tree_is_internal_node(void *ptr)
#define RADIX_TREE_MAX_TAGS 3
-#ifndef RADIX_TREE_MAP_SHIFT
-#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6)
-#endif
-
+#define RADIX_TREE_MAP_SHIFT XA_CHUNK_SHIFT
#define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT)
#define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1)
@@ -95,36 +95,21 @@ struct radix_tree_node {
unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
};
-/* The IDR tag is stored in the low bits of the GFP flags */
+/* The IDR tag is stored in the low bits of xa_flags */
#define ROOT_IS_IDR ((__force gfp_t)4)
-/* The top bits of gfp_mask are used to store the root tags */
+/* The top bits of xa_flags are used to store the root tags */
#define ROOT_TAG_SHIFT (__GFP_BITS_SHIFT)
-struct radix_tree_root {
- spinlock_t xa_lock;
- gfp_t gfp_mask;
- struct radix_tree_node __rcu *rnode;
-};
-
-#define RADIX_TREE_INIT(name, mask) { \
- .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock), \
- .gfp_mask = (mask), \
- .rnode = NULL, \
-}
+#define RADIX_TREE_INIT(name, mask) XARRAY_INIT_FLAGS(name, mask)
#define RADIX_TREE(name, mask) \
struct radix_tree_root name = RADIX_TREE_INIT(name, mask)
-#define INIT_RADIX_TREE(root, mask) \
-do { \
- spin_lock_init(&(root)->xa_lock); \
- (root)->gfp_mask = (mask); \
- (root)->rnode = NULL; \
-} while (0)
+#define INIT_RADIX_TREE(root, mask) xa_init_flags(root, mask)
static inline bool radix_tree_empty(const struct radix_tree_root *root)
{
- return root->rnode == NULL;
+ return root->xa_head == NULL;
}
/**
@@ -10,6 +10,8 @@
*/
#include <linux/bug.h>
+#include <linux/compiler.h>
+#include <linux/kconfig.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -105,6 +107,65 @@ static inline bool xa_is_internal(const void *entry)
return ((unsigned long)entry & 3) == 2;
}
+/**
+ * struct xarray - The anchor of the XArray.
+ * @xa_lock: Lock that protects the contents of the XArray.
+ *
+ * To use the xarray, define it statically or embed it in your data structure.
+ * It is a very small data structure, so it does not usually make sense to
+ * allocate it separately and keep a pointer to it in your data structure.
+ *
+ * You may use the xa_lock to protect your own data structures as well.
+ */
+/*
+ * If all of the entries in the array are NULL, @xa_head is a NULL pointer.
+ * If the only non-NULL entry in the array is at index 0, @xa_head is that
+ * entry. If any other entry in the array is non-NULL, @xa_head points
+ * to an @xa_node.
+ */
+struct xarray {
+ spinlock_t xa_lock;
+/* private: The rest of the data structure is not to be used directly. */
+ gfp_t xa_flags;
+ void __rcu * xa_head;
+};
+
+#define XARRAY_INIT_FLAGS(name, flags) { \
+ .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock), \
+ .xa_flags = flags, \
+ .xa_head = NULL, \
+}
+
+#define XARRAY_INIT(name) XARRAY_INIT_FLAGS(name, 0)
+
+/**
+ * DEFINE_XARRAY() - Define an XArray
+ * @name: A string that names your XArray
+ *
+ * This is intended for file scope definitions of XArrays. It declares
+ * and initialises an empty XArray with the chosen name. It is equivalent
+ * to calling xa_init() on the array, but it does the initialisation at
+ * compiletime instead of runtime.
+ */
+#define DEFINE_XARRAY(name) struct xarray name = XARRAY_INIT(name)
+#define DEFINE_XARRAY_FLAGS(name, flags) \
+ struct xarray name = XARRAY_INIT_FLAGS(name, flags)
+
+void xa_init_flags(struct xarray *, gfp_t flags);
+
+/**
+ * xa_init() - Initialise an empty XArray.
+ * @xa: XArray.
+ *
+ * An empty XArray is full of NULL entries.
+ *
+ * Context: Any context.
+ */
+static inline void xa_init(struct xarray *xa)
+{
+ xa_init_flags(xa, 0);
+}
+
#define xa_trylock(xa) spin_trylock(&(xa)->xa_lock)
#define xa_lock(xa) spin_lock(&(xa)->xa_lock)
#define xa_unlock(xa) spin_unlock(&(xa)->xa_lock)
@@ -18,7 +18,7 @@ KCOV_INSTRUMENT_debugobjects.o := n
KCOV_INSTRUMENT_dynamic_debug.o := n
lib-y := ctype.o string.o vsprintf.o cmdline.o \
- rbtree.o radix-tree.o timerqueue.o\
+ rbtree.o radix-tree.o timerqueue.o xarray.o \
idr.o int_sqrt.o extable.o \
sha1.o chacha20.o irq_regs.o argv_split.o \
flex_proportions.o ratelimit.o show_mem.o \
@@ -42,8 +42,8 @@ int idr_alloc_u32(struct idr *idr, void *ptr, u32 *nextid,
if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr)))
return -EINVAL;
- if (WARN_ON_ONCE(!(idr->idr_rt.gfp_mask & ROOT_IS_IDR)))
- idr->idr_rt.gfp_mask |= IDR_RT_MARKER;
+ if (WARN_ON_ONCE(!(idr->idr_rt.xa_flags & ROOT_IS_IDR)))
+ idr->idr_rt.xa_flags |= IDR_RT_MARKER;
id = (id < base) ? 0 : id - base;
radix_tree_iter_init(&iter, id);
@@ -124,7 +124,7 @@ static unsigned int radix_tree_descend(const struct radix_tree_node *parent,
static inline gfp_t root_gfp_mask(const struct radix_tree_root *root)
{
- return root->gfp_mask & (__GFP_BITS_MASK & ~GFP_ZONEMASK);
+ return root->xa_flags & (__GFP_BITS_MASK & ~GFP_ZONEMASK);
}
static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
@@ -147,32 +147,32 @@ static inline int tag_get(const struct radix_tree_node *node, unsigned int tag,
static inline void root_tag_set(struct radix_tree_root *root, unsigned tag)
{
- root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT));
+ root->xa_flags |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT));
}
static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag)
{
- root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT));
+ root->xa_flags &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT));
}
static inline void root_tag_clear_all(struct radix_tree_root *root)
{
- root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1;
+ root->xa_flags &= (__force gfp_t)((1 << ROOT_TAG_SHIFT) - 1);
}
static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag)
{
- return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT));
+ return (__force int)root->xa_flags & (1 << (tag + ROOT_TAG_SHIFT));
}
static inline unsigned root_tags_get(const struct radix_tree_root *root)
{
- return (__force unsigned)root->gfp_mask >> ROOT_TAG_SHIFT;
+ return (__force unsigned)root->xa_flags >> ROOT_TAG_SHIFT;
}
static inline bool is_idr(const struct radix_tree_root *root)
{
- return !!(root->gfp_mask & ROOT_IS_IDR);
+ return !!(root->xa_flags & ROOT_IS_IDR);
}
/*
@@ -291,12 +291,12 @@ static void dump_node(struct radix_tree_node *node, unsigned long index)
/* For debug */
static void radix_tree_dump(struct radix_tree_root *root)
{
- pr_debug("radix root: %p rnode %p tags %x\n",
- root, root->rnode,
- root->gfp_mask >> ROOT_TAG_SHIFT);
- if (!radix_tree_is_internal_node(root->rnode))
+ pr_debug("radix root: %p xa_head %p tags %x\n",
+ root, root->xa_head,
+ root->xa_flags >> ROOT_TAG_SHIFT);
+ if (!radix_tree_is_internal_node(root->xa_head))
return;
- dump_node(entry_to_node(root->rnode), 0);
+ dump_node(entry_to_node(root->xa_head), 0);
}
static void dump_ida_node(void *entry, unsigned long index)
@@ -340,9 +340,9 @@ static void dump_ida_node(void *entry, unsigned long index)
static void ida_dump(struct ida *ida)
{
struct radix_tree_root *root = &ida->ida_rt;
- pr_debug("ida: %p node %p free %d\n", ida, root->rnode,
- root->gfp_mask >> ROOT_TAG_SHIFT);
- dump_ida_node(root->rnode, 0);
+ pr_debug("ida: %p node %p free %d\n", ida, root->xa_head,
+ root->xa_flags >> ROOT_TAG_SHIFT);
+ dump_ida_node(root->xa_head, 0);
}
#endif
@@ -576,7 +576,7 @@ int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order)
static unsigned radix_tree_load_root(const struct radix_tree_root *root,
struct radix_tree_node **nodep, unsigned long *maxindex)
{
- struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
+ struct radix_tree_node *node = rcu_dereference_raw(root->xa_head);
*nodep = node;
@@ -605,7 +605,7 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp,
while (index > shift_maxindex(maxshift))
maxshift += RADIX_TREE_MAP_SHIFT;
- entry = rcu_dereference_raw(root->rnode);
+ entry = rcu_dereference_raw(root->xa_head);
if (!entry && (!is_idr(root) || root_tag_get(root, IDR_FREE)))
goto out;
@@ -633,7 +633,7 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp,
if (radix_tree_is_internal_node(entry)) {
entry_to_node(entry)->parent = node;
} else if (xa_is_value(entry)) {
- /* Moving an exceptional root->rnode to a node */
+ /* Moving an exceptional root->xa_head to a node */
node->exceptional = 1;
}
/*
@@ -642,7 +642,7 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp,
*/
node->slots[0] = (void __rcu *)entry;
entry = node_to_entry(node);
- rcu_assign_pointer(root->rnode, entry);
+ rcu_assign_pointer(root->xa_head, entry);
shift += RADIX_TREE_MAP_SHIFT;
} while (shift <= maxshift);
out:
@@ -659,7 +659,7 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root,
bool shrunk = false;
for (;;) {
- struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
+ struct radix_tree_node *node = rcu_dereference_raw(root->xa_head);
struct radix_tree_node *child;
if (!radix_tree_is_internal_node(node))
@@ -687,9 +687,9 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root,
* moving the node from one part of the tree to another: if it
* was safe to dereference the old pointer to it
* (node->slots[0]), it will be safe to dereference the new
- * one (root->rnode) as far as dependent read barriers go.
+ * one (root->xa_head) as far as dependent read barriers go.
*/
- root->rnode = (void __rcu *)child;
+ root->xa_head = (void __rcu *)child;
if (is_idr(root) && !tag_get(node, IDR_FREE, 0))
root_tag_clear(root, IDR_FREE);
@@ -737,9 +737,8 @@ static bool delete_node(struct radix_tree_root *root,
if (node->count) {
if (node_to_entry(node) ==
- rcu_dereference_raw(root->rnode))
- deleted |= radix_tree_shrink(root,
- update_node);
+ rcu_dereference_raw(root->xa_head))
+ deleted |= radix_tree_shrink(root, update_node);
return deleted;
}
@@ -754,7 +753,7 @@ static bool delete_node(struct radix_tree_root *root,
*/
if (!is_idr(root))
root_tag_clear_all(root);
- root->rnode = NULL;
+ root->xa_head = NULL;
}
WARN_ON_ONCE(!list_empty(&node->private_list));
@@ -779,7 +778,7 @@ static bool delete_node(struct radix_tree_root *root,
* at position @index in the radix tree @root.
*
* Until there is more than one item in the tree, no nodes are
- * allocated and @root->rnode is used as a direct slot instead of
+ * allocated and @root->xa_head is used as a direct slot instead of
* pointing to a node, in which case *@nodep will be NULL.
*
* Returns -ENOMEM, or 0 for success.
@@ -789,7 +788,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
void __rcu ***slotp)
{
struct radix_tree_node *node = NULL, *child;
- void __rcu **slot = (void __rcu **)&root->rnode;
+ void __rcu **slot = (void __rcu **)&root->xa_head;
unsigned long maxindex;
unsigned int shift, offset = 0;
unsigned long max = index | ((1UL << order) - 1);
@@ -805,7 +804,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
if (error < 0)
return error;
shift = error;
- child = rcu_dereference_raw(root->rnode);
+ child = rcu_dereference_raw(root->xa_head);
}
while (shift > order) {
@@ -996,7 +995,7 @@ EXPORT_SYMBOL(__radix_tree_insert);
* tree @root.
*
* Until there is more than one item in the tree, no nodes are
- * allocated and @root->rnode is used as a direct slot instead of
+ * allocated and @root->xa_head is used as a direct slot instead of
* pointing to a node, in which case *@nodep will be NULL.
*/
void *__radix_tree_lookup(const struct radix_tree_root *root,
@@ -1009,7 +1008,7 @@ void *__radix_tree_lookup(const struct radix_tree_root *root,
restart:
parent = NULL;
- slot = (void __rcu **)&root->rnode;
+ slot = (void __rcu **)&root->xa_head;
radix_tree_load_root(root, &node, &maxindex);
if (index > maxindex)
return NULL;
@@ -1161,9 +1160,9 @@ void __radix_tree_replace(struct radix_tree_root *root,
/*
* This function supports replacing exceptional entries and
* deleting entries, but that needs accounting against the
- * node unless the slot is root->rnode.
+ * node unless the slot is root->xa_head.
*/
- WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->rnode) &&
+ WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->xa_head) &&
(count || exceptional));
replace_slot(slot, item, node, count, exceptional);
@@ -1715,7 +1714,7 @@ void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root,
iter->tags = 1;
iter->node = NULL;
__set_iter_shift(iter, 0);
- return (void __rcu **)&root->rnode;
+ return (void __rcu **)&root->xa_head;
}
do {
@@ -2109,7 +2108,7 @@ void __rcu **idr_get_free(struct radix_tree_root *root,
unsigned long max)
{
struct radix_tree_node *node = NULL, *child;
- void __rcu **slot = (void __rcu **)&root->rnode;
+ void __rcu **slot = (void __rcu **)&root->xa_head;
unsigned long maxindex, start = iter->next_index;
unsigned int shift, offset = 0;
@@ -2125,7 +2124,7 @@ void __rcu **idr_get_free(struct radix_tree_root *root,
if (error < 0)
return ERR_PTR(error);
shift = error;
- child = rcu_dereference_raw(root->rnode);
+ child = rcu_dereference_raw(root->xa_head);
}
while (shift) {
@@ -2188,10 +2187,10 @@ void __rcu **idr_get_free(struct radix_tree_root *root,
*/
void idr_destroy(struct idr *idr)
{
- struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode);
+ struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.xa_head);
if (radix_tree_is_internal_node(node))
radix_tree_free_nodes(node);
- idr->idr_rt.rnode = NULL;
+ idr->idr_rt.xa_head = NULL;
root_tag_set(&idr->idr_rt, IDR_FREE);
}
EXPORT_SYMBOL(idr_destroy);
new file mode 100644
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * XArray implementation
+ * Copyright (c) 2017 Microsoft Corporation
+ * Author: Matthew Wilcox <mawilcox@microsoft.com>
+ */
+
+#include <linux/export.h>
+#include <linux/xarray.h>
+
+/*
+ * Coding conventions in this file:
+ *
+ * @xa is used to refer to the entire xarray.
+ * @xas is the 'xarray operation state'. It may be either a pointer to
+ * an xa_state, or an xa_state stored on the stack. This is an unfortunate
+ * ambiguity.
+ * @index is the index of the entry being operated on
+ * @tag is an xa_tag_t; a small number indicating one of the tag bits.
+ * @node refers to an xa_node; usually the primary one being operated on by
+ * this function.
+ * @offset is the index into the slots array inside an xa_node.
+ * @parent refers to the @xa_node closer to the head than @node.
+ * @entry refers to something stored in a slot in the xarray
+ */
+
+/**
+ * xa_init_flags() - Initialise an empty XArray with flags.
+ * @xa: XArray.
+ * @flags: XA_FLAG values.
+ *
+ * If you need to initialise an XArray with special flags (eg you need
+ * to take the lock from interrupt context), use this function instead
+ * of xa_init().
+ *
+ * Context: Any context.
+ */
+void xa_init_flags(struct xarray *xa, gfp_t flags)
+{
+ spin_lock_init(&xa->xa_lock);
+ xa->xa_flags = flags;
+ xa->xa_head = NULL;
+}
+EXPORT_SYMBOL(xa_init_flags);
@@ -6,8 +6,9 @@
#include <stdbool.h>
#define spinlock_t pthread_mutex_t
-#define DEFINE_SPINLOCK(x) pthread_mutex_t x = PTHREAD_MUTEX_INITIALIZER;
+#define DEFINE_SPINLOCK(x) pthread_mutex_t x = PTHREAD_MUTEX_INITIALIZER
#define __SPIN_LOCK_UNLOCKED(x) (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER
+#define spin_lock_init(x) pthread_mutex_init(x, NULL)
#define spin_lock_irqsave(x, f) (void)f, pthread_mutex_lock(x)
#define spin_unlock_irqrestore(x, f) (void)f, pthread_mutex_unlock(x)
@@ -4,3 +4,4 @@ idr-test
main
multiorder
radix-tree.c
+xarray.c
@@ -4,7 +4,7 @@ CFLAGS += -I. -I../../include -g -O2 -Wall -D_LGPL_SOURCE -fsanitize=address
LDFLAGS += -fsanitize=address
LDLIBS+= -lpthread -lurcu
TARGETS = main idr-test multiorder
-CORE_OFILES := radix-tree.o idr.o linux.o test.o find_bit.o
+CORE_OFILES := xarray.o radix-tree.o idr.o linux.o test.o find_bit.o
OFILES = main.o $(CORE_OFILES) regression1.o regression2.o regression3.o \
tag_check.o multiorder.o idr-test.o iteration_check.o benchmark.o
@@ -33,9 +33,13 @@ vpath %.c ../../lib
$(OFILES): Makefile *.h */*.h generated/map-shift.h \
../../include/linux/*.h \
../../include/asm/*.h \
+ ../../../include/linux/xarray.h \
../../../include/linux/radix-tree.h \
../../../include/linux/idr.h
+xarray.c: ../../../lib/xarray.c
+ sed -e 's/^static //' -e 's/__always_inline //' -e 's/inline //' < $< > $@
+
radix-tree.c: ../../../lib/radix-tree.c
sed -e 's/^static //' -e 's/__always_inline //' -e 's/inline //' < $< > $@
@@ -46,6 +50,6 @@ idr.c: ../../../lib/idr.c
mapshift:
@if ! grep -qws $(SHIFT) generated/map-shift.h; then \
- echo "#define RADIX_TREE_MAP_SHIFT $(SHIFT)" > \
+ echo "#define XA_CHUNK_SHIFT $(SHIFT)" > \
generated/map-shift.h; \
fi
@@ -1 +1,2 @@
+#include <stdio.h>
#include "asm/bug.h"
new file mode 100644
@@ -0,0 +1 @@
+#include "../../../../include/linux/kconfig.h"
new file mode 100644
@@ -0,0 +1,2 @@
+#include "generated/map-shift.h"
+#include "../../../../include/linux/xarray.h"
@@ -191,13 +191,13 @@ static void multiorder_shrink(unsigned long index, int order)
assert(item_insert_order(&tree, 0, order) == 0);
- node = tree.rnode;
+ node = tree.xa_head;
assert(item_insert(&tree, index) == 0);
- assert(node != tree.rnode);
+ assert(node != tree.xa_head);
assert(item_delete(&tree, index) != 0);
- assert(node == tree.rnode);
+ assert(node == tree.xa_head);
for (i = 0; i < max; i++) {
struct item *item = item_lookup(&tree, i);
@@ -262,7 +262,7 @@ static int verify_node(struct radix_tree_node *slot, unsigned int tag,
void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag)
{
- struct radix_tree_node *node = root->rnode;
+ struct radix_tree_node *node = root->xa_head;
if (!radix_tree_is_internal_node(node))
return;
verify_node(node, tag, !!root_tag_get(root, tag));
@@ -292,13 +292,13 @@ void item_kill_tree(struct radix_tree_root *root)
}
}
assert(radix_tree_gang_lookup(root, (void **)items, 0, 32) == 0);
- assert(root->rnode == NULL);
+ assert(root->xa_head == NULL);
}
void tree_verify_min_height(struct radix_tree_root *root, int maxindex)
{
unsigned shift;
- struct radix_tree_node *node = root->rnode;
+ struct radix_tree_node *node = root->xa_head;
if (!radix_tree_is_internal_node(node)) {
assert(maxindex == 0);
return;