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Remove dead code from AVL tree 

The avl_update_* functions are never used by ZFS and are therefore
being removed.  They're barely even used in Illumos.  Additionally,
simplify avl_add() by using a VERIFY which produces exactly the same
behavior under Linux.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6716
This commit is contained in:
Brian Behlendorf 2017-10-05 19:28:00 -07:00 committed by GitHub
parent 39f56627ae
commit c11f1004d1
2 changed files with 4 additions and 82 deletions
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11
include/sys/avl.h
View File

@ -259,17 +259,6 @@ extern void avl_add(avl_tree_t *tree, void *node);
*/
extern void avl_remove(avl_tree_t *tree, void *node);
/*
* Reinsert a node only if its order has changed relative to its nearest
* neighbors. To optimize performance avl_update_lt() checks only the previous
* node and avl_update_gt() checks only the next node. Use avl_update_lt() and
* avl_update_gt() only if you know the direction in which the order of the
* node may change.
*/
extern boolean_t avl_update(avl_tree_t *, void *);
extern boolean_t avl_update_lt(avl_tree_t *, void *);
extern boolean_t avl_update_gt(avl_tree_t *, void *);
/*
* Swaps the contents of the two trees.
*/

75
module/avl/avl.c
View File

@ -626,25 +626,16 @@ avl_insert_here(
}
/*
* Add a new node to an AVL tree.
* Add a new node to an AVL tree. Strictly enforce that no duplicates can
* be added to the tree with a VERIFY which is enabled for non-DEBUG builds.
*/
void
avl_add(avl_tree_t *tree, void *new_node)
{
avl_index_t where = 0;
/*
* This is unfortunate. We want to call panic() here, even for
* non-DEBUG kernels. In userland, however, we can't depend on anything
* in libc or else the rtld build process gets confused. So, all we can
* do in userland is resort to a normal ASSERT().
*/
if (avl_find(tree, new_node, &where) != NULL)
#ifdef _KERNEL
panic("avl_find() succeeded inside avl_add()");
#else
ASSERT(0);
#endif
VERIFY(avl_find(tree, new_node, &where) == NULL);
avl_insert(tree, new_node, where);
}
@ -817,64 +808,6 @@ avl_remove(avl_tree_t *tree, void *data)
} while (parent != NULL);
}
#define AVL_REINSERT(tree, obj) \
avl_remove((tree), (obj)); \
avl_add((tree), (obj))
boolean_t
avl_update_lt(avl_tree_t *t, void *obj)
{
void *neighbor;
ASSERT(((neighbor = AVL_NEXT(t, obj)) == NULL) ||
(t->avl_compar(obj, neighbor) <= 0));
neighbor = AVL_PREV(t, obj);
if ((neighbor != NULL) && (t->avl_compar(obj, neighbor) < 0)) {
AVL_REINSERT(t, obj);
return (B_TRUE);
}
return (B_FALSE);
}
boolean_t
avl_update_gt(avl_tree_t *t, void *obj)
{
void *neighbor;
ASSERT(((neighbor = AVL_PREV(t, obj)) == NULL) ||
(t->avl_compar(obj, neighbor) >= 0));
neighbor = AVL_NEXT(t, obj);
if ((neighbor != NULL) && (t->avl_compar(obj, neighbor) > 0)) {
AVL_REINSERT(t, obj);
return (B_TRUE);
}
return (B_FALSE);
}
boolean_t
avl_update(avl_tree_t *t, void *obj)
{
void *neighbor;
neighbor = AVL_PREV(t, obj);
if ((neighbor != NULL) && (t->avl_compar(obj, neighbor) < 0)) {
AVL_REINSERT(t, obj);
return (B_TRUE);
}
neighbor = AVL_NEXT(t, obj);
if ((neighbor != NULL) && (t->avl_compar(obj, neighbor) > 0)) {
AVL_REINSERT(t, obj);
return (B_TRUE);
}
return (B_FALSE);
}
void
avl_swap(avl_tree_t *tree1, avl_tree_t *tree2)
{