On 04/14/2018 09:12 AM, Matthew Wilcox wrote:
> From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
>
> This iterator allows the user to efficiently walk a range of the array,
> executing the loop body once for each entry in that range that matches
> the filter. This commit also includes xa_find() and xa_find_above()
> which are helper functions for xa_for_each() but may also be useful in
> their own right.
>
> In the xas family of functions, we also have xas_for_each(), xas_find(),
> xas_next_entry(), xas_for_each_tag(), xas_find_tag(), xas_next_tag()
> and xas_pause().
>
> Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
> ---
> include/linux/xarray.h | 175 ++++++++++++++++
> lib/xarray.c | 274 +++++++++++++++++++++++++
> tools/testing/radix-tree/test.c | 13 ++
> tools/testing/radix-tree/test.h | 1 +
> tools/testing/radix-tree/xarray-test.c | 122 +++++++++++
> 5 files changed, 585 insertions(+)
>
> diff --git a/include/linux/xarray.h b/include/linux/xarray.h
> index 78acafe109ab..4162dadef9b2 100644
> --- a/include/linux/xarray.h
> +++ b/include/linux/xarray.h
> @@ -223,6 +223,10 @@ void *xa_cmpxchg(struct xarray *, unsigned long index,
> bool xa_get_tag(struct xarray *, unsigned long index, xa_tag_t);
> void xa_set_tag(struct xarray *, unsigned long index, xa_tag_t);
> void xa_clear_tag(struct xarray *, unsigned long index, xa_tag_t);
> +void *xa_find(struct xarray *xa, unsigned long *index,
> + unsigned long max, xa_tag_t) __attribute__((nonnull(2)));
> +void *xa_find_after(struct xarray *xa, unsigned long *index,
> + unsigned long max, xa_tag_t) __attribute__((nonnull(2)));
>
> /**
> * xa_init() - Initialise an empty XArray.
> @@ -279,6 +283,35 @@ static inline bool xa_tagged(const struct xarray *xa, xa_tag_t tag)
> return xa->xa_flags & XA_FLAGS_TAG(tag);
> }
>
> +/**
> + * xa_for_each() - Iterate over a portion of an XArray.
> + * @xa: XArray.
> + * @entry: Entry retrieved from array.
> + * @index: Index of @entry.
> + * @max: Maximum index to retrieve from array.
> + * @filter: Selection criterion.
> + *
> + * Initialise @index to the minimum index you want to retrieve from
> + * the array. During the iteration, @entry will have the value of the
> + * entry stored in @xa at @index. The iteration will skip all entries in
> + * the array which do not match @filter. You may modify @index during the
> + * iteration if you want to skip or reprocess indices. It is safe to modify
> + * the array during the iteration. At the end of the iteration, @entry will
> + * be set to NULL and @index will have a value less than or equal to max.
> + *
> + * xa_for_each() is O(n.log(n)) while xas_for_each() is O(n). You have
> + * to handle your own locking with xas_for_each(), and if you have to unlock
> + * after each iteration, it will also end up being O(n.log(n)). xa_for_each()
> + * will spin if it hits a retry entry; if you intend to see retry entries,
> + * you should use the xas_for_each() iterator instead. The xas_for_each()
> + * iterator will expand into more inline code than xa_for_each().
> + *
> + * Context: Any context. Takes and releases the RCU lock.
> + */
> +#define xa_for_each(xa, entry, index, max, filter) \
> + for (entry = xa_find(xa, &index, max, filter); entry; \
> + entry = xa_find_after(xa, &index, max, filter))
> +
> /**
> * xa_insert() - Store this entry in the XArray unless another entry is
> * already present.
> @@ -658,6 +691,12 @@ static inline bool xas_valid(const struct xa_state *xas)
> return !xas_invalid(xas);
> }
>
> +/* True if the pointer is something other than a node */
> +static inline bool xas_not_node(struct xa_node *node)
> +{
> + return ((unsigned long)node & 3) || !node;
> +}
> +
> /* True if the node represents head-of-tree, RESTART or BOUNDS */
> static inline bool xas_top(struct xa_node *node)
> {
> @@ -702,13 +741,16 @@ static inline bool xas_retry(struct xa_state *xas, const void *entry)
> void *xas_load(struct xa_state *);
> void *xas_store(struct xa_state *, void *entry);
> void *xas_create(struct xa_state *);
> +void *xas_find(struct xa_state *, unsigned long max);
>
> bool xas_get_tag(const struct xa_state *, xa_tag_t);
> void xas_set_tag(const struct xa_state *, xa_tag_t);
> void xas_clear_tag(const struct xa_state *, xa_tag_t);
> +void *xas_find_tag(struct xa_state *, unsigned long max, xa_tag_t);
> void xas_init_tags(const struct xa_state *);
>
> bool xas_nomem(struct xa_state *, gfp_t);
> +void xas_pause(struct xa_state *);
>
> /**
> * xas_reload() - Refetch an entry from the xarray.
> @@ -781,6 +823,139 @@ static inline void xas_set_update(struct xa_state *xas, xa_update_node_t update)
> xas->xa_update = update;
> }
>
> +/* Skip over any of these entries when iterating */
> +static inline bool xa_iter_skip(const void *entry)
> +{
> + return unlikely(!entry ||
> + (xa_is_internal(entry) && entry < XA_RETRY_ENTRY));
> +}
> +
> +/**
> + * xas_next_entry() - Advance iterator to next present entry.
> + * @xas: XArray operation state.
> + * @max: Highest index to return.
> + *
> + * xas_next_entry() is an inline function to optimise xarray traversal for
> + * speed. It is equivalent to calling xas_find(), and will call xas_find()
> + * for all the hard cases.
> + *
> + * Return: The next present entry after the one currently referred to by @xas.
> + */
> +static inline void *xas_next_entry(struct xa_state *xas, unsigned long max)
> +{
> + struct xa_node *node = xas->xa_node;
> + void *entry;
> +
> + if (unlikely(xas_not_node(node) || node->shift))
> + return xas_find(xas, max);
> +
> + do {
> + if (unlikely(xas->xa_index >= max))
> + return xas_find(xas, max);
> + if (unlikely(xas->xa_offset == XA_CHUNK_MASK))
> + return xas_find(xas, max);
> + xas->xa_index++;
> + xas->xa_offset++;
> + entry = xa_entry(xas->xa, node, xas->xa_offset);
> + } while (xa_iter_skip(entry));
> +
> + return entry;
> +}
> +
> +/* Private */
> +static inline unsigned int xas_find_chunk(struct xa_state *xas, bool advance,
> + xa_tag_t tag)
> +{
> + unsigned long *addr = xas->xa_node->tags[(__force unsigned)tag];
> + unsigned int offset = xas->xa_offset;
> +
> + if (advance)
> + offset++;
> + if (XA_CHUNK_SIZE == BITS_PER_LONG) {
> + if (offset < XA_CHUNK_SIZE) {
> + unsigned long data = *addr & (~0UL << offset);
> + if (data)
> + return __ffs(data);
> + }
> + return XA_CHUNK_SIZE;
> + }
> +
> + return find_next_bit(addr, XA_CHUNK_SIZE, offset);
> +}
> +
> +/**
> + * xas_next_tag() - Advance iterator to next tagged entry.
> + * @xas: XArray operation state.
> + * @max: Highest index to return.
> + * @tag: Tag to search for.
> + *
> + * xas_next_tag() is an inline function to optimise xarray traversal for
> + * speed. It is equivalent to calling xas_find_tag(), and will call
> + * xas_find_tag() for all the hard cases.
> + *
> + * Return: The next tagged entry after the one currently referred to by @xas.
> + */
> +static inline void *xas_next_tag(struct xa_state *xas, unsigned long max,
> + xa_tag_t tag)
> +{
> + struct xa_node *node = xas->xa_node;
> + unsigned int offset;
> +
> + if (unlikely(xas_not_node(node) || node->shift))
> + return xas_find_tag(xas, max, tag);
> + offset = xas_find_chunk(xas, true, tag);
> + xas->xa_offset = offset;
> + xas->xa_index = (xas->xa_index & ~XA_CHUNK_MASK) + offset;
> + if (xas->xa_index > max)
> + return NULL;
> + if (offset == XA_CHUNK_SIZE)
> + return xas_find_tag(xas, max, tag);
> + return xa_entry(xas->xa, node, offset);
> +}
> +
> +/*
> + * If iterating while holding a lock, drop the lock and reschedule
> + * every %XA_CHECK_SCHED loops.
> + */
> +enum {
> + XA_CHECK_SCHED = 4096,
> +};
> +
> +/**
> + * xas_for_each() - Iterate over a range of an XArray
> + * @xas: XArray operation state.
> + * @entry: Entry retrieved from array.
> + * @max: Maximum index to retrieve from array.
> + *
> + * The loop body will be executed for each entry present in the xarray
> + * between the current xas position and @max. @entry will be set to
> + * the entry retrieved from the xarray. It is safe to delete entries
> + * from the array in the loop body. You should hold either the RCU lock
> + * or the xa_lock while iterating. If you need to drop the lock, call
> + * xas_pause() first.
> + */
> +#define xas_for_each(xas, entry, max) \
> + for (entry = xas_find(xas, max); entry; \
> + entry = xas_next_entry(xas, max))
> +
> +/**
> + * xas_for_each_tag() - Iterate over a range of an XArray
> + * @xas: XArray operation state.
> + * @entry: Entry retrieved from array.
> + * @max: Maximum index to retrieve from array.
> + * @tag: Tag to search for.
> + *
> + * The loop body will be executed for each tagged entry in the xarray
> + * between the current xas position and @max. @entry will be set to
> + * the entry retrieved from the xarray. It is safe to delete entries
> + * from the array in the loop body. You should hold either the RCU lock
> + * or the xa_lock while iterating. If you need to drop the lock, call
> + * xas_pause() first.
> + */
> +#define xas_for_each_tag(xas, entry, max, tag) \
> + for (entry = xas_find_tag(xas, max, tag); entry; \
> + entry = xas_next_tag(xas, max, tag))
> +
This function name sounds like you are performing the operation for each
tag.
Can it be called xas_for_each_tagged() or xas_tag_for_each() instead?
> /* Internal functions, mostly shared between radix-tree.c, xarray.c and idr.c */
> void xas_destroy(struct xa_state *);
>
> diff --git a/lib/xarray.c b/lib/xarray.c
> index c9228a0953d7..73cf4c984c2d 100644
> --- a/lib/xarray.c
> +++ b/lib/xarray.c
> @@ -91,6 +91,11 @@ static unsigned int get_offset(unsigned long index, struct xa_node *node)
> return (index >> node->shift) & XA_CHUNK_MASK;
> }
>
> +static void xas_set_offset(struct xa_state *xas)
> +{
> + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node);
> +}
> +
> /* move the index either forwards (find) or backwards (sibling slot) */
> static void xas_move_index(struct xa_state *xas, unsigned long offset)
> {
> @@ -99,6 +104,12 @@ static void xas_move_index(struct xa_state *xas, unsigned long offset)
> xas->xa_index += offset << shift;
> }
>
> +static void xas_advance(struct xa_state *xas)
> +{
> + xas->xa_offset++;
> + xas_move_index(xas, xas->xa_offset);
> +}
> +
> static void *set_bounds(struct xa_state *xas)
> {
> xas->xa_node = XAS_BOUNDS;
> @@ -805,6 +816,191 @@ void xas_init_tags(const struct xa_state *xas)
> }
> EXPORT_SYMBOL_GPL(xas_init_tags);
>
> +/**
> + * xas_pause() - Pause a walk to drop a lock.
> + * @xas: XArray operation state.
> + *
> + * Some users need to pause a walk and drop the lock they're holding in
> + * order to yield to a higher priority thread or carry out an operation
> + * on an entry. Those users should call this function before they drop
> + * the lock. It resets the @xas to be suitable for the next iteration
> + * of the loop after the user has reacquired the lock. If most entries
> + * found during a walk require you to call xas_pause(), the xa_for_each()
> + * iterator may be more appropriate.
> + *
> + * Note that xas_pause() only works for forward iteration. If a user needs
> + * to pause a reverse iteration, we will need a xas_pause_rev().
> + */
> +void xas_pause(struct xa_state *xas)
> +{
> + struct xa_node *node = xas->xa_node;
> +
> + if (xas_invalid(xas))
> + return;
> +
> + if (node) {
> + unsigned int offset = xas->xa_offset;
> + while (++offset < XA_CHUNK_SIZE) {
> + if (!xa_is_sibling(xa_entry(xas->xa, node, offset)))
> + break;
> + }
> + xas->xa_index += (offset - xas->xa_offset) << node->shift;
> + } else {
> + xas->xa_index++;
> + }
> + xas->xa_node = XAS_RESTART;
> +}
> +EXPORT_SYMBOL_GPL(xas_pause);
> +
> +/**
> + * xas_find() - Find the next present entry in the XArray.
> + * @xas: XArray operation state.
> + * @max: Highest index to return.
> + *
> + * If the xas has not yet been walked to an entry, return the entry
> + * which has an index >= xas.xa_index. If it has been walked, the entry
> + * currently being pointed at has been processed, and so we move to the
> + * next entry.
> + *
> + * If no entry is found and the array is smaller than @max, the iterator
> + * is set to the smallest index not yet in the array. This allows @xas
> + * to be immediately passed to xas_create().
> + *
> + * Return: The entry, if found, otherwise NULL.
> + */
> +void *xas_find(struct xa_state *xas, unsigned long max)
> +{
> + void *entry;
> +
> + if (xas_error(xas))
> + return NULL;
> +
> + if (!xas->xa_node) {
> + xas->xa_index = 1;
> + return set_bounds(xas);
> + } else if (xas_top(xas->xa_node)) {
> + entry = xas_load(xas);
> + if (entry || xas_not_node(xas->xa_node))
> + return entry;
> + }
> +
> + xas_advance(xas);
> +
> + while (xas->xa_node && (xas->xa_index <= max)) {
> + if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) {
> + xas->xa_offset = xas->xa_node->offset + 1;
> + xas->xa_node = xa_parent(xas->xa, xas->xa_node);
> + continue;
> + }
> +
> + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
> + if (xa_is_node(entry)) {
> + xas->xa_node = xa_to_node(entry);
> + xas->xa_offset = 0;
> + continue;
> + }
> + if (!xa_iter_skip(entry))
> + return entry;
> +
> + xas_advance(xas);
> + }
> +
> + if (!xas->xa_node)
> + xas->xa_node = XAS_BOUNDS;
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(xas_find);
> +
> +/**
> + * xas_find_tag() - Find the next tagged entry in the XArray.
> + * @xas: XArray operation state.
> + * @max: Highest index to return.
> + * @tag: Tag number to search for.
> + *
> + * If the xas has not yet been walked to an entry, return the tagged entry
> + * which has an index >= xas.xa_index. If it has been walked, the entry
> + * currently being pointed at has been processed, and so we move to the
> + * next tagged entry.
> + *
> + * If no tagged entry is found and the array is smaller than @max, @xas is
> + * set to the bounds state and xas->xa_index is set to the smallest index
> + * not yet in the array. This allows @xas to be immediately passed to
> + * xas_create().
> + *
> + * Return: The entry, if found, otherwise %NULL.
> + */
> +void *xas_find_tag(struct xa_state *xas, unsigned long max, xa_tag_t tag)
> +{
> + bool advance = true;
> + unsigned int offset;
> + void *entry;
> +
> + if (xas_error(xas))
> + return NULL;
> +
> + if (!xas->xa_node) {
> + xas->xa_index = 1;
> + goto out;
> + } else if (xas_top(xas->xa_node)) {
> + advance = false;
> + entry = xa_head(xas->xa);
> + if (xas->xa_index > max_index(entry))
> + goto out;
> + if (!xa_is_node(entry)) {
> + if (xa_tagged(xas->xa, tag)) {
> + xas->xa_node = NULL;
> + return entry;
> + }
> + xas->xa_index = 1;
> + goto out;
> + }
> + xas->xa_node = xa_to_node(entry);
> + xas->xa_offset = xas->xa_index >> xas->xa_node->shift;
> + }
> +
> + while (xas->xa_index <= max) {
> + if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) {
> + xas->xa_offset = xas->xa_node->offset + 1;
> + xas->xa_node = xa_parent(xas->xa, xas->xa_node);
> + if (!xas->xa_node)
> + break;
> + advance = false;
> + continue;
> + }
> +
> + if (!advance) {
> + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
> + if (xa_is_sibling(entry)) {
> + xas->xa_offset = xa_to_sibling(entry);
> + xas_move_index(xas, xas->xa_offset);
> + }
> + }
> +
> + offset = xas_find_chunk(xas, advance, tag);
> + if (offset > xas->xa_offset) {
> + advance = false;
> + xas_move_index(xas, offset);
> + xas->xa_offset = offset;
> + if (offset == XA_CHUNK_SIZE)
> + continue;
> + if (xas->xa_index > max)
> + break;
> + }
> +
> + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
> + if (!xa_is_node(entry))
> + return entry;
> + xas->xa_node = xa_to_node(entry);
> + xas_set_offset(xas);
> + }
> +
> + out:
> + if (!xas->xa_node)
> + xas->xa_node = XAS_BOUNDS;
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(xas_find_tag);
> +
> /**
> * xa_init_flags() - Initialise an empty XArray with flags.
> * @xa: XArray.
> @@ -1128,6 +1324,84 @@ void xa_clear_tag(struct xarray *xa, unsigned long index, xa_tag_t tag)
> }
> EXPORT_SYMBOL(xa_clear_tag);
>
> +/**
> + * xa_find() - Search the XArray for an entry.
> + * @xa: XArray.
> + * @indexp: Pointer to an index.
> + * @max: Maximum index to search to.
> + * @filter: Selection criterion.
> + *
> + * Finds the entry in @xa which matches the @filter, and has the lowest
> + * index that is at least @indexp and no more than @max.
> + * If an entry is found, @indexp is updated to be the index of the entry.
> + * This function is protected by the RCU read lock, so it may not find
> + * entries which are being simultaneously added. It will not return an
> + * %XA_RETRY_ENTRY; if you need to see retry entries, use xas_find().
> + *
> + * Context: Any context. Takes and releases the RCU lock.
> + * Return: The entry, if found, otherwise NULL.
> + */
> +void *xa_find(struct xarray *xa, unsigned long *indexp,
> + unsigned long max, xa_tag_t filter)
> +{
> + XA_STATE(xas, xa, *indexp);
> + void *entry;
> +
> + rcu_read_lock();
> + do {
> + if ((__force unsigned int)filter < XA_MAX_TAGS)
> + entry = xas_find_tag(&xas, max, filter);
> + else
> + entry = xas_find(&xas, max);
> + } while (xas_retry(&xas, entry));
> + rcu_read_unlock();
> +
> + if (entry)
> + *indexp = xas.xa_index;
> + return entry;
> +}
> +EXPORT_SYMBOL(xa_find);
> +
> +/**
> + * xa_find_after() - Search the XArray for a present entry.
> + * @xa: XArray.
> + * @indexp: Pointer to an index.
> + * @max: Maximum index to search to.
> + * @filter: Selection criterion.
> + *
> + * Finds the entry in @xa which matches the @filter and has the lowest
> + * index that is above @indexp and no more than @max.
> + * If an entry is found, @indexp is updated to be the index of the entry.
> + * This function is protected by the RCU read lock, so it may miss entries
> + * which are being simultaneously added. It will not return an
> + * %XA_RETRY_ENTRY; if you need to see retry entries, use xas_find().
> + *
> + * Context: Any context. Takes and releases the RCU lock.
> + * Return: The pointer, if found, otherwise NULL.
> + */
> +void *xa_find_after(struct xarray *xa, unsigned long *indexp,
> + unsigned long max, xa_tag_t filter)
> +{
> + XA_STATE(xas, xa, *indexp + 1);
> + void *entry;
> +
> + rcu_read_lock();
> + do {
> + if ((__force unsigned int)filter < XA_MAX_TAGS)
> + entry = xas_find_tag(&xas, max, filter);
> + else
> + entry = xas_find(&xas, max);
> + if (*indexp >= xas.xa_index)
> + entry = xas_next_entry(&xas, max);
> + } while (xas_retry(&xas, entry));
> + rcu_read_unlock();
> +
> + if (entry)
> + *indexp = xas.xa_index;
> + return entry;
> +}
> +EXPORT_SYMBOL(xa_find_after);
> +
> #ifdef XA_DEBUG
> void xa_dump_node(const struct xa_node *node)
> {
> diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c
> index f151588d04a0..e9b4a4ed9bf5 100644
> --- a/tools/testing/radix-tree/test.c
> +++ b/tools/testing/radix-tree/test.c
> @@ -244,6 +244,19 @@ unsigned long find_item(struct radix_tree_root *root, void *item)
> return found;
> }
>
> +static LIST_HEAD(item_nodes);
> +
> +void item_update_node(struct xa_node *node)
> +{
> + if (node->count) {
> + if (list_empty(&node->private_list))
> + list_add(&node->private_list, &item_nodes);
> + } else {
> + if (!list_empty(&node->private_list))
> + list_del_init(&node->private_list);
> + }
> +}
> +
> static int verify_node(struct radix_tree_node *slot, unsigned int tag,
> int tagged)
> {
> diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
> index ffd162645c11..f97cacd1422d 100644
> --- a/tools/testing/radix-tree/test.h
> +++ b/tools/testing/radix-tree/test.h
> @@ -30,6 +30,7 @@ void item_gang_check_present(struct radix_tree_root *root,
> void item_full_scan(struct radix_tree_root *root, unsigned long start,
> unsigned long nr, int chunk);
> void item_kill_tree(struct radix_tree_root *root);
> +void item_update_node(struct xa_node *node);
>
> int tag_tagged_items(struct radix_tree_root *, pthread_mutex_t *,
> unsigned long start, unsigned long end, unsigned batch,
> diff --git a/tools/testing/radix-tree/xarray-test.c b/tools/testing/radix-tree/xarray-test.c
> index d71603bfa41d..90c49e0f06aa 100644
> --- a/tools/testing/radix-tree/xarray-test.c
> +++ b/tools/testing/radix-tree/xarray-test.c
> @@ -42,6 +42,29 @@ void check_xa_tag(struct xarray *xa)
> assert(xa_get_tag(xa, 0, XA_TAG_0) == false);
> }
>
> +void check_xas_retry(struct xarray *xa)
> +{
> + XA_STATE(xas, xa, 0);
> +
> + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL);
> + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL);
> +
> + assert(xas_find(&xas, ULONG_MAX) == xa_mk_value(0));
> + xa_erase(xa, 1);
> + assert(xa_is_retry(xas_reload(&xas)));
> + assert(!xas_retry(&xas, NULL));
> + assert(!xas_retry(&xas, xa_mk_value(0)));
> + assert(xas_retry(&xas, XA_RETRY_ENTRY));
> + assert(xas.xa_node == XAS_RESTART);
> + assert(xas_next_entry(&xas, ULONG_MAX) == xa_mk_value(0));
> + assert(xas.xa_node == NULL);
> +
> + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL);
> + assert(xa_is_internal(xas_reload(&xas)));
> + xas.xa_node = XAS_RESTART;
> + assert(xas_next_entry(&xas, ULONG_MAX) == xa_mk_value(0));
> +}
> +
> void check_xa_load(struct xarray *xa)
> {
> unsigned long i, j;
> @@ -179,6 +202,98 @@ void check_multi_load(struct xarray *xa)
> __check_multi_load(xa, 8192, 13);
> }
>
> +void check_multi_find(struct xarray *xa)
> +{
> + unsigned long index;
> + xa_store_order(xa, 12, 2, xa_mk_value(12), GFP_KERNEL);
> + xa_store(xa, 16, xa_mk_value(16), GFP_KERNEL);
> +
> + index = 0;
> + assert(xa_find(xa, &index, ULONG_MAX, XA_PRESENT) == xa_mk_value(12));
> + assert(index == 12);
> + index = 13;
> + assert(xa_find(xa, &index, ULONG_MAX, XA_PRESENT) == xa_mk_value(12));
> + assert(index >= 12 && index < 16);
> + assert(xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) == xa_mk_value(16));
> + assert(index == 16);
> + xa_erase(xa, 12);
> + xa_erase(xa, 16);
> + assert(xa_empty(xa));
> +}
> +
> +void check_find(struct xarray *xa)
> +{
> + unsigned long i, j, k;
> +
> + assert(xa_empty(xa));
> +
> + for (i = 0; i < 100; i++) {
> + xa_store(xa, i, xa_mk_value(i), GFP_KERNEL);
> + xa_set_tag(xa, i, XA_TAG_0);
> + for (j = 0; j < i; j++) {
> + xa_store(xa, j, xa_mk_value(j), GFP_KERNEL);
> + xa_set_tag(xa, j, XA_TAG_0);
> + for (k = 0; k < 100; k++) {
> + unsigned long index = k;
> + void *entry = xa_find(xa, &index, ULONG_MAX,
> + XA_PRESENT);
> + if (k <= j)
> + assert(index == j);
> + else if (k <= i)
> + assert(index == i);
> + else
> + assert(entry == NULL);
> +
> + index = k;
> + entry = xa_find(xa, &index, ULONG_MAX,
> + XA_TAG_0);
> + if (k <= j)
> + assert(index == j);
> + else if (k <= i)
> + assert(index == i);
> + else
> + assert(entry == NULL);
> + }
> + xa_erase(xa, j);
> + }
> + xa_erase(xa, i);
> + }
> + assert(xa_empty(xa));
> + check_multi_find(xa);
> +}
> +
> +void check_xas_delete(struct xarray *xa)
> +{
> + XA_STATE(xas, xa, 0);
> + void *entry;
> + unsigned long i, j;
> +
> + xas_set_update(&xas, item_update_node);
> + for (i = 0; i < 200; i++) {
> + for (j = i; j < 2 * i + 17; j++) {
> + xas_set(&xas, j);
> + do {
> + xas_store(&xas, xa_mk_value(j));
> + } while (xas_nomem(&xas, GFP_KERNEL));
> + }
> +
> + xas_set(&xas, ULONG_MAX);
> + do {
> + xas_store(&xas, xa_mk_value(0));
> + } while (xas_nomem(&xas, GFP_KERNEL));
> + xas_store(&xas, NULL);
> +
> + xas_set(&xas, 0);
> + j = i;
> + xas_for_each(&xas, entry, ULONG_MAX) {
> + assert(entry == xa_mk_value(j));
> + xas_store(&xas, NULL);
> + j++;
> + }
> + assert(xa_empty(xa));
> + }
> +}
> +
> void xarray_checks(void)
> {
> DEFINE_XARRAY(array);
> @@ -189,6 +304,9 @@ void xarray_checks(void)
> check_xa_tag(&array);
> item_kill_tree(&array);
>
> + check_xas_retry(&array);
> + item_kill_tree(&array);
> +
> check_xa_load(&array);
> item_kill_tree(&array);
>
> @@ -199,6 +317,10 @@ void xarray_checks(void)
> check_multi_store(&array);
> item_kill_tree(&array);
> check_multi_load(&array);
> +
> + check_find(&array);
> + check_xas_delete(&array);
> + item_kill_tree(&array);
> }
>
> int __weak main(void)
>
--
Goldwyn
