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prio_tree: remove
After both prio_tree users have been converted to use red-black trees, there is no need to keep around the prio tree library anymore. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michel Lespinasse
Linus Torvalds
parent
85d3a316c7
commit
147e615f83
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@ -270,8 +270,6 @@ preempt-locking.txt
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- info on locking under a preemptive kernel.
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printk-formats.txt
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- how to get printk format specifiers right
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prio_tree.txt
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- info on radix-priority-search-tree use for indexing vmas.
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ramoops.txt
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- documentation of the ramoops oops/panic logging module.
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rbtree.txt
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@ -1,107 +0,0 @@
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The prio_tree.c code indexes vmas using 3 different indexes:
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* heap_index = vm_pgoff + vm_size_in_pages : end_vm_pgoff
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* radix_index = vm_pgoff : start_vm_pgoff
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* size_index = vm_size_in_pages
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A regular radix-priority-search-tree indexes vmas using only heap_index and
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radix_index. The conditions for indexing are:
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* ->heap_index >= ->left->heap_index &&
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->heap_index >= ->right->heap_index
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* if (->heap_index == ->left->heap_index)
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then ->radix_index < ->left->radix_index;
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* if (->heap_index == ->right->heap_index)
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then ->radix_index < ->right->radix_index;
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* nodes are hashed to left or right subtree using radix_index
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similar to a pure binary radix tree.
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A regular radix-priority-search-tree helps to store and query
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intervals (vmas). However, a regular radix-priority-search-tree is only
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suitable for storing vmas with different radix indices (vm_pgoff).
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Therefore, the prio_tree.c extends the regular radix-priority-search-tree
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to handle many vmas with the same vm_pgoff. Such vmas are handled in
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2 different ways: 1) All vmas with the same radix _and_ heap indices are
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linked using vm_set.list, 2) if there are many vmas with the same radix
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index, but different heap indices and if the regular radix-priority-search
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tree cannot index them all, we build an overflow-sub-tree that indexes such
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vmas using heap and size indices instead of heap and radix indices. For
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example, in the figure below some vmas with vm_pgoff = 0 (zero) are
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indexed by regular radix-priority-search-tree whereas others are pushed
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into an overflow-subtree. Note that all vmas in an overflow-sub-tree have
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the same vm_pgoff (radix_index) and if necessary we build different
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overflow-sub-trees to handle each possible radix_index. For example,
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in figure we have 3 overflow-sub-trees corresponding to radix indices
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0, 2, and 4.
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In the final tree the first few (prio_tree_root->index_bits) levels
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are indexed using heap and radix indices whereas the overflow-sub-trees below
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those levels (i.e. levels prio_tree_root->index_bits + 1 and higher) are
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indexed using heap and size indices. In overflow-sub-trees the size_index
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is used for hashing the nodes to appropriate places.
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Now, an example prio_tree:
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vmas are represented [radix_index, size_index, heap_index]
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i.e., [start_vm_pgoff, vm_size_in_pages, end_vm_pgoff]
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level prio_tree_root->index_bits = 3
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-----
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_
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0 [0,7,7] |
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/ \ |
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------------------ ------------ | Regular
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/ \ | radix priority
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1 [1,6,7] [4,3,7] | search tree
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/ \ / \ |
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------- ----- ------ ----- | heap-and-radix
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/ \ / \ | indexed
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2 [0,6,6] [2,5,7] [5,2,7] [6,1,7] |
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/ \ / \ / \ / \ |
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3 [0,5,5] [1,5,6] [2,4,6] [3,4,7] [4,2,6] [5,1,6] [6,0,6] [7,0,7] |
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/ / / _
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/ / / _
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4 [0,4,4] [2,3,5] [4,1,5] |
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/ / / |
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5 [0,3,3] [2,2,4] [4,0,4] | Overflow-sub-trees
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/ / |
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6 [0,2,2] [2,1,3] | heap-and-size
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/ / | indexed
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7 [0,1,1] [2,0,2] |
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/ |
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8 [0,0,0] |
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_
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Note that we use prio_tree_root->index_bits to optimize the height
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of the heap-and-radix indexed tree. Since prio_tree_root->index_bits is
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set according to the maximum end_vm_pgoff mapped, we are sure that all
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bits (in vm_pgoff) above prio_tree_root->index_bits are 0 (zero). Therefore,
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we only use the first prio_tree_root->index_bits as radix_index.
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Whenever index_bits is increased in prio_tree_expand, we shuffle the tree
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to make sure that the first prio_tree_root->index_bits levels of the tree
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is indexed properly using heap and radix indices.
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We do not optimize the height of overflow-sub-trees using index_bits.
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The reason is: there can be many such overflow-sub-trees and all of
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them have to be suffled whenever the index_bits increases. This may involve
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walking the whole prio_tree in prio_tree_insert->prio_tree_expand code
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path which is not desirable. Hence, we do not optimize the height of the
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heap-and-size indexed overflow-sub-trees using prio_tree->index_bits.
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Instead the overflow sub-trees are indexed using full BITS_PER_LONG bits
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of size_index. This may lead to skewed sub-trees because most of the
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higher significant bits of the size_index are likely to be 0 (zero). In
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the example above, all 3 overflow-sub-trees are skewed. This may marginally
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affect the performance. However, processes rarely map many vmas with the
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same start_vm_pgoff but different end_vm_pgoffs. Therefore, we normally
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do not require overflow-sub-trees to index all vmas.
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From the above discussion it is clear that the maximum height of
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a prio_tree can be prio_tree_root->index_bits + BITS_PER_LONG.
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However, in most of the common cases we do not need overflow-sub-trees,
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so the tree height in the common cases will be prio_tree_root->index_bits.
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It is fair to mention here that the prio_tree_root->index_bits
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is increased on demand, however, the index_bits is not decreased when
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vmas are removed from the prio_tree. That's tricky to do. Hence, it's
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left as a home work problem.
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@ -1,120 +0,0 @@
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#ifndef _LINUX_PRIO_TREE_H
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#define _LINUX_PRIO_TREE_H
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/*
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* K&R 2nd ed. A8.3 somewhat obliquely hints that initial sequences of struct
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* fields with identical types should end up at the same location. We'll use
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* this until we can scrap struct raw_prio_tree_node.
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*
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* Note: all this could be done more elegantly by using unnamed union/struct
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* fields. However, gcc 2.95.3 and apparently also gcc 3.0.4 don't support this
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* language extension.
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*/
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struct raw_prio_tree_node {
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struct prio_tree_node *left;
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struct prio_tree_node *right;
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struct prio_tree_node *parent;
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};
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struct prio_tree_node {
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struct prio_tree_node *left;
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struct prio_tree_node *right;
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struct prio_tree_node *parent;
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unsigned long start;
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unsigned long last; /* last location _in_ interval */
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};
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struct prio_tree_root {
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struct prio_tree_node *prio_tree_node;
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unsigned short index_bits;
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unsigned short raw;
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/*
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* 0: nodes are of type struct prio_tree_node
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* 1: nodes are of type raw_prio_tree_node
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*/
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};
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struct prio_tree_iter {
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struct prio_tree_node *cur;
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unsigned long mask;
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unsigned long value;
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int size_level;
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struct prio_tree_root *root;
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pgoff_t r_index;
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pgoff_t h_index;
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};
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static inline void prio_tree_iter_init(struct prio_tree_iter *iter,
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struct prio_tree_root *root, pgoff_t r_index, pgoff_t h_index)
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{
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iter->root = root;
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iter->r_index = r_index;
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iter->h_index = h_index;
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iter->cur = NULL;
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}
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#define __INIT_PRIO_TREE_ROOT(ptr, _raw) \
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do { \
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(ptr)->prio_tree_node = NULL; \
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(ptr)->index_bits = 1; \
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(ptr)->raw = (_raw); \
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} while (0)
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#define INIT_PRIO_TREE_ROOT(ptr) __INIT_PRIO_TREE_ROOT(ptr, 0)
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#define INIT_RAW_PRIO_TREE_ROOT(ptr) __INIT_PRIO_TREE_ROOT(ptr, 1)
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#define INIT_PRIO_TREE_NODE(ptr) \
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do { \
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(ptr)->left = (ptr)->right = (ptr)->parent = (ptr); \
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} while (0)
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#define INIT_PRIO_TREE_ITER(ptr) \
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do { \
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(ptr)->cur = NULL; \
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(ptr)->mask = 0UL; \
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(ptr)->value = 0UL; \
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(ptr)->size_level = 0; \
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} while (0)
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#define prio_tree_entry(ptr, type, member) \
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((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
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static inline int prio_tree_empty(const struct prio_tree_root *root)
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{
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return root->prio_tree_node == NULL;
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}
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static inline int prio_tree_root(const struct prio_tree_node *node)
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{
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return node->parent == node;
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}
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static inline int prio_tree_left_empty(const struct prio_tree_node *node)
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{
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return node->left == node;
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}
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static inline int prio_tree_right_empty(const struct prio_tree_node *node)
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{
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return node->right == node;
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}
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struct prio_tree_node *prio_tree_replace(struct prio_tree_root *root,
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struct prio_tree_node *old, struct prio_tree_node *node);
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struct prio_tree_node *prio_tree_insert(struct prio_tree_root *root,
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struct prio_tree_node *node);
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void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node);
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struct prio_tree_node *prio_tree_next(struct prio_tree_iter *iter);
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#define raw_prio_tree_replace(root, old, node) \
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prio_tree_replace(root, (struct prio_tree_node *) (old), \
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(struct prio_tree_node *) (node))
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#define raw_prio_tree_insert(root, node) \
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prio_tree_insert(root, (struct prio_tree_node *) (node))
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#define raw_prio_tree_remove(root, node) \
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prio_tree_remove(root, (struct prio_tree_node *) (node))
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#endif /* _LINUX_PRIO_TREE_H */
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@ -86,7 +86,6 @@ extern void init_IRQ(void);
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extern void fork_init(unsigned long);
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extern void mca_init(void);
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extern void sbus_init(void);
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extern void prio_tree_init(void);
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extern void radix_tree_init(void);
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#ifndef CONFIG_DEBUG_RODATA
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static inline void mark_rodata_ro(void) { }
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@ -547,7 +546,6 @@ asmlinkage void __init start_kernel(void)
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/* init some links before init_ISA_irqs() */
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early_irq_init();
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init_IRQ();
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prio_tree_init();
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init_timers();
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hrtimers_init();
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softirq_init();
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@ -1289,12 +1289,6 @@ config RBTREE_TEST
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A benchmark measuring the performance of the rbtree library.
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Also includes rbtree invariant checks.
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config PRIO_TREE_TEST
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tristate "Prio tree test"
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depends on m && DEBUG_KERNEL
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help
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A benchmark measuring the performance of the prio tree library
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config INTERVAL_TREE_TEST
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tristate "Interval tree test"
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depends on m && DEBUG_KERNEL
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@ -9,7 +9,7 @@ endif
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lib-y := ctype.o string.o vsprintf.o cmdline.o \
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rbtree.o radix-tree.o dump_stack.o timerqueue.o\
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idr.o int_sqrt.o extable.o prio_tree.o \
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idr.o int_sqrt.o extable.o \
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sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
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proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
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is_single_threaded.o plist.o decompress.o
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@ -141,7 +141,6 @@ $(foreach file, $(libfdt_files), \
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lib-$(CONFIG_LIBFDT) += $(libfdt_files)
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obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o
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obj-$(CONFIG_PRIO_TREE_TEST) += prio_tree_test.o
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obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o
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interval_tree_test-objs := interval_tree_test_main.o interval_tree.o
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455
lib/prio_tree.c
455
lib/prio_tree.c
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@ -1,455 +0,0 @@
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/*
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* lib/prio_tree.c - priority search tree
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*
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* Copyright (C) 2004, Rajesh Venkatasubramanian <vrajesh@umich.edu>
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*
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* This file is released under the GPL v2.
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*
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* Based on the radix priority search tree proposed by Edward M. McCreight
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* SIAM Journal of Computing, vol. 14, no.2, pages 257-276, May 1985
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*
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* 02Feb2004 Initial version
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*/
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/prio_tree.h>
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#include <linux/export.h>
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/*
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* A clever mix of heap and radix trees forms a radix priority search tree (PST)
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* which is useful for storing intervals, e.g, we can consider a vma as a closed
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* interval of file pages [offset_begin, offset_end], and store all vmas that
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* map a file in a PST. Then, using the PST, we can answer a stabbing query,
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* i.e., selecting a set of stored intervals (vmas) that overlap with (map) a
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* given input interval X (a set of consecutive file pages), in "O(log n + m)"
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* time where 'log n' is the height of the PST, and 'm' is the number of stored
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* intervals (vmas) that overlap (map) with the input interval X (the set of
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* consecutive file pages).
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*
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* In our implementation, we store closed intervals of the form [radix_index,
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* heap_index]. We assume that always radix_index <= heap_index. McCreight's PST
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* is designed for storing intervals with unique radix indices, i.e., each
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* interval have different radix_index. However, this limitation can be easily
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* overcome by using the size, i.e., heap_index - radix_index, as part of the
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* index, so we index the tree using [(radix_index,size), heap_index].
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*
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* When the above-mentioned indexing scheme is used, theoretically, in a 32 bit
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* machine, the maximum height of a PST can be 64. We can use a balanced version
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* of the priority search tree to optimize the tree height, but the balanced
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* tree proposed by McCreight is too complex and memory-hungry for our purpose.
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*/
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/*
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* The following macros are used for implementing prio_tree for i_mmap
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*/
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static void get_index(const struct prio_tree_root *root,
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const struct prio_tree_node *node,
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unsigned long *radix, unsigned long *heap)
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{
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*radix = node->start;
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*heap = node->last;
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}
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static unsigned long index_bits_to_maxindex[BITS_PER_LONG];
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void __init prio_tree_init(void)
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{
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unsigned int i;
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for (i = 0; i < ARRAY_SIZE(index_bits_to_maxindex) - 1; i++)
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index_bits_to_maxindex[i] = (1UL << (i + 1)) - 1;
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index_bits_to_maxindex[ARRAY_SIZE(index_bits_to_maxindex) - 1] = ~0UL;
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}
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/*
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* Maximum heap_index that can be stored in a PST with index_bits bits
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*/
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static inline unsigned long prio_tree_maxindex(unsigned int bits)
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{
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return index_bits_to_maxindex[bits - 1];
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}
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static void prio_set_parent(struct prio_tree_node *parent,
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struct prio_tree_node *child, bool left)
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{
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if (left)
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parent->left = child;
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else
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parent->right = child;
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child->parent = parent;
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}
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/*
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* Extend a priority search tree so that it can store a node with heap_index
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* max_heap_index. In the worst case, this algorithm takes O((log n)^2).
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* However, this function is used rarely and the common case performance is
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* not bad.
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*/
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static struct prio_tree_node *prio_tree_expand(struct prio_tree_root *root,
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struct prio_tree_node *node, unsigned long max_heap_index)
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{
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struct prio_tree_node *prev;
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if (max_heap_index > prio_tree_maxindex(root->index_bits))
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root->index_bits++;
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prev = node;
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INIT_PRIO_TREE_NODE(node);
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while (max_heap_index > prio_tree_maxindex(root->index_bits)) {
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struct prio_tree_node *tmp = root->prio_tree_node;
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root->index_bits++;
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if (prio_tree_empty(root))
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continue;
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prio_tree_remove(root, root->prio_tree_node);
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INIT_PRIO_TREE_NODE(tmp);
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|
||||
prio_set_parent(prev, tmp, true);
|
||||
prev = tmp;
|
||||
}
|
||||
|
||||
if (!prio_tree_empty(root))
|
||||
prio_set_parent(prev, root->prio_tree_node, true);
|
||||
|
||||
root->prio_tree_node = node;
|
||||
return node;
|
||||
}
|
||||
|
||||
/*
|
||||
* Replace a prio_tree_node with a new node and return the old node
|
||||
*/
|
||||
struct prio_tree_node *prio_tree_replace(struct prio_tree_root *root,
|
||||
struct prio_tree_node *old, struct prio_tree_node *node)
|
||||
{
|
||||
INIT_PRIO_TREE_NODE(node);
|
||||
|
||||
if (prio_tree_root(old)) {
|
||||
BUG_ON(root->prio_tree_node != old);
|
||||
/*
|
||||
* We can reduce root->index_bits here. However, it is complex
|
||||
* and does not help much to improve performance (IMO).
|
||||
*/
|
||||
root->prio_tree_node = node;
|
||||
} else
|
||||
prio_set_parent(old->parent, node, old->parent->left == old);
|
||||
|
||||
if (!prio_tree_left_empty(old))
|
||||
prio_set_parent(node, old->left, true);
|
||||
|
||||
if (!prio_tree_right_empty(old))
|
||||
prio_set_parent(node, old->right, false);
|
||||
|
||||
return old;
|
||||
}
|
||||
|
||||
/*
|
||||
* Insert a prio_tree_node @node into a radix priority search tree @root. The
|
||||
* algorithm typically takes O(log n) time where 'log n' is the number of bits
|
||||
* required to represent the maximum heap_index. In the worst case, the algo
|
||||
* can take O((log n)^2) - check prio_tree_expand.
|
||||
*
|
||||
* If a prior node with same radix_index and heap_index is already found in
|
||||
* the tree, then returns the address of the prior node. Otherwise, inserts
|
||||
* @node into the tree and returns @node.
|
||||
*/
|
||||
struct prio_tree_node *prio_tree_insert(struct prio_tree_root *root,
|
||||
struct prio_tree_node *node)
|
||||
{
|
||||
struct prio_tree_node *cur, *res = node;
|
||||
unsigned long radix_index, heap_index;
|
||||
unsigned long r_index, h_index, index, mask;
|
||||
int size_flag = 0;
|
||||
|
||||
get_index(root, node, &radix_index, &heap_index);
|
||||
|
||||
if (prio_tree_empty(root) ||
|
||||
heap_index > prio_tree_maxindex(root->index_bits))
|
||||
return prio_tree_expand(root, node, heap_index);
|
||||
|
||||
cur = root->prio_tree_node;
|
||||
mask = 1UL << (root->index_bits - 1);
|
||||
|
||||
while (mask) {
|
||||
get_index(root, cur, &r_index, &h_index);
|
||||
|
||||
if (r_index == radix_index && h_index == heap_index)
|
||||
return cur;
|
||||
|
||||
if (h_index < heap_index ||
|
||||
(h_index == heap_index && r_index > radix_index)) {
|
||||
struct prio_tree_node *tmp = node;
|
||||
node = prio_tree_replace(root, cur, node);
|
||||
cur = tmp;
|
||||
/* swap indices */
|
||||
index = r_index;
|
||||
r_index = radix_index;
|
||||
radix_index = index;
|
||||
index = h_index;
|
||||
h_index = heap_index;
|
||||
heap_index = index;
|
||||
}
|
||||
|
||||
if (size_flag)
|
||||
index = heap_index - radix_index;
|
||||
else
|
||||
index = radix_index;
|
||||
|
||||
if (index & mask) {
|
||||
if (prio_tree_right_empty(cur)) {
|
||||
INIT_PRIO_TREE_NODE(node);
|
||||
prio_set_parent(cur, node, false);
|
||||
return res;
|
||||
} else
|
||||
cur = cur->right;
|
||||
} else {
|
||||
if (prio_tree_left_empty(cur)) {
|
||||
INIT_PRIO_TREE_NODE(node);
|
||||
prio_set_parent(cur, node, true);
|
||||
return res;
|
||||
} else
|
||||
cur = cur->left;
|
||||
}
|
||||
|
||||
mask >>= 1;
|
||||
|
||||
if (!mask) {
|
||||
mask = 1UL << (BITS_PER_LONG - 1);
|
||||
size_flag = 1;
|
||||
}
|
||||
}
|
||||
/* Should not reach here */
|
||||
BUG();
|
||||
return NULL;
|
||||
}
|
||||
EXPORT_SYMBOL(prio_tree_insert);
|
||||
|
||||
/*
|
||||
* Remove a prio_tree_node @node from a radix priority search tree @root. The
|
||||
* algorithm takes O(log n) time where 'log n' is the number of bits required
|
||||
* to represent the maximum heap_index.
|
||||
*/
|
||||
void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node)
|
||||
{
|
||||
struct prio_tree_node *cur;
|
||||
unsigned long r_index, h_index_right, h_index_left;
|
||||
|
||||
cur = node;
|
||||
|
||||
while (!prio_tree_left_empty(cur) || !prio_tree_right_empty(cur)) {
|
||||
if (!prio_tree_left_empty(cur))
|
||||
get_index(root, cur->left, &r_index, &h_index_left);
|
||||
else {
|
||||
cur = cur->right;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (!prio_tree_right_empty(cur))
|
||||
get_index(root, cur->right, &r_index, &h_index_right);
|
||||
else {
|
||||
cur = cur->left;
|
||||
continue;
|
||||
}
|
||||
|
||||
/* both h_index_left and h_index_right cannot be 0 */
|
||||
if (h_index_left >= h_index_right)
|
||||
cur = cur->left;
|
||||
else
|
||||
cur = cur->right;
|
||||
}
|
||||
|
||||
if (prio_tree_root(cur)) {
|
||||
BUG_ON(root->prio_tree_node != cur);
|
||||
__INIT_PRIO_TREE_ROOT(root, root->raw);
|
||||
return;
|
||||
}
|
||||
|
||||
if (cur->parent->right == cur)
|
||||
cur->parent->right = cur->parent;
|
||||
else
|
||||
cur->parent->left = cur->parent;
|
||||
|
||||
while (cur != node)
|
||||
cur = prio_tree_replace(root, cur->parent, cur);
|
||||
}
|
||||
EXPORT_SYMBOL(prio_tree_remove);
|
||||
|
||||
static void iter_walk_down(struct prio_tree_iter *iter)
|
||||
{
|
||||
iter->mask >>= 1;
|
||||
if (iter->mask) {
|
||||
if (iter->size_level)
|
||||
iter->size_level++;
|
||||
return;
|
||||
}
|
||||
|
||||
if (iter->size_level) {
|
||||
BUG_ON(!prio_tree_left_empty(iter->cur));
|
||||
BUG_ON(!prio_tree_right_empty(iter->cur));
|
||||
iter->size_level++;
|
||||
iter->mask = ULONG_MAX;
|
||||
} else {
|
||||
iter->size_level = 1;
|
||||
iter->mask = 1UL << (BITS_PER_LONG - 1);
|
||||
}
|
||||
}
|
||||
|
||||
static void iter_walk_up(struct prio_tree_iter *iter)
|
||||
{
|
||||
if (iter->mask == ULONG_MAX)
|
||||
iter->mask = 1UL;
|
||||
else if (iter->size_level == 1)
|
||||
iter->mask = 1UL;
|
||||
else
|
||||
iter->mask <<= 1;
|
||||
if (iter->size_level)
|
||||
iter->size_level--;
|
||||
if (!iter->size_level && (iter->value & iter->mask))
|
||||
iter->value ^= iter->mask;
|
||||
}
|
||||
|
||||
/*
|
||||
* Following functions help to enumerate all prio_tree_nodes in the tree that
|
||||
* overlap with the input interval X [radix_index, heap_index]. The enumeration
|
||||
* takes O(log n + m) time where 'log n' is the height of the tree (which is
|
||||
* proportional to # of bits required to represent the maximum heap_index) and
|
||||
* 'm' is the number of prio_tree_nodes that overlap the interval X.
|
||||
*/
|
||||
|
||||
static struct prio_tree_node *prio_tree_left(struct prio_tree_iter *iter,
|
||||
unsigned long *r_index, unsigned long *h_index)
|
||||
{
|
||||
if (prio_tree_left_empty(iter->cur))
|
||||
return NULL;
|
||||
|
||||
get_index(iter->root, iter->cur->left, r_index, h_index);
|
||||
|
||||
if (iter->r_index <= *h_index) {
|
||||
iter->cur = iter->cur->left;
|
||||
iter_walk_down(iter);
|
||||
return iter->cur;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static struct prio_tree_node *prio_tree_right(struct prio_tree_iter *iter,
|
||||
unsigned long *r_index, unsigned long *h_index)
|
||||
{
|
||||
unsigned long value;
|
||||
|
||||
if (prio_tree_right_empty(iter->cur))
|
||||
return NULL;
|
||||
|
||||
if (iter->size_level)
|
||||
value = iter->value;
|
||||
else
|
||||
value = iter->value | iter->mask;
|
||||
|
||||
if (iter->h_index < value)
|
||||
return NULL;
|
||||
|
||||
get_index(iter->root, iter->cur->right, r_index, h_index);
|
||||
|
||||
if (iter->r_index <= *h_index) {
|
||||
iter->cur = iter->cur->right;
|
||||
iter_walk_down(iter);
|
||||
return iter->cur;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static struct prio_tree_node *prio_tree_parent(struct prio_tree_iter *iter)
|
||||
{
|
||||
iter->cur = iter->cur->parent;
|
||||
iter_walk_up(iter);
|
||||
return iter->cur;
|
||||
}
|
||||
|
||||
static inline int overlap(struct prio_tree_iter *iter,
|
||||
unsigned long r_index, unsigned long h_index)
|
||||
{
|
||||
return iter->h_index >= r_index && iter->r_index <= h_index;
|
||||
}
|
||||
|
||||
/*
|
||||
* prio_tree_first:
|
||||
*
|
||||
* Get the first prio_tree_node that overlaps with the interval [radix_index,
|
||||
* heap_index]. Note that always radix_index <= heap_index. We do a pre-order
|
||||
* traversal of the tree.
|
||||
*/
|
||||
static struct prio_tree_node *prio_tree_first(struct prio_tree_iter *iter)
|
||||
{
|
||||
struct prio_tree_root *root;
|
||||
unsigned long r_index, h_index;
|
||||
|
||||
INIT_PRIO_TREE_ITER(iter);
|
||||
|
||||
root = iter->root;
|
||||
if (prio_tree_empty(root))
|
||||
return NULL;
|
||||
|
||||
get_index(root, root->prio_tree_node, &r_index, &h_index);
|
||||
|
||||
if (iter->r_index > h_index)
|
||||
return NULL;
|
||||
|
||||
iter->mask = 1UL << (root->index_bits - 1);
|
||||
iter->cur = root->prio_tree_node;
|
||||
|
||||
while (1) {
|
||||
if (overlap(iter, r_index, h_index))
|
||||
return iter->cur;
|
||||
|
||||
if (prio_tree_left(iter, &r_index, &h_index))
|
||||
continue;
|
||||
|
||||
if (prio_tree_right(iter, &r_index, &h_index))
|
||||
continue;
|
||||
|
||||
break;
|
||||
}
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* prio_tree_next:
|
||||
*
|
||||
* Get the next prio_tree_node that overlaps with the input interval in iter
|
||||
*/
|
||||
struct prio_tree_node *prio_tree_next(struct prio_tree_iter *iter)
|
||||
{
|
||||
unsigned long r_index, h_index;
|
||||
|
||||
if (iter->cur == NULL)
|
||||
return prio_tree_first(iter);
|
||||
|
||||
repeat:
|
||||
while (prio_tree_left(iter, &r_index, &h_index))
|
||||
if (overlap(iter, r_index, h_index))
|
||||
return iter->cur;
|
||||
|
||||
while (!prio_tree_right(iter, &r_index, &h_index)) {
|
||||
while (!prio_tree_root(iter->cur) &&
|
||||
iter->cur->parent->right == iter->cur)
|
||||
prio_tree_parent(iter);
|
||||
|
||||
if (prio_tree_root(iter->cur))
|
||||
return NULL;
|
||||
|
||||
prio_tree_parent(iter);
|
||||
}
|
||||
|
||||
if (overlap(iter, r_index, h_index))
|
||||
return iter->cur;
|
||||
|
||||
goto repeat;
|
||||
}
|
||||
EXPORT_SYMBOL(prio_tree_next);
|
||||
|
|
@ -1,106 +0,0 @@
|
|||
#include <linux/module.h>
|
||||
#include <linux/prio_tree.h>
|
||||
#include <linux/random.h>
|
||||
#include <asm/timex.h>
|
||||
|
||||
#define NODES 100
|
||||
#define PERF_LOOPS 100000
|
||||
#define SEARCHES 100
|
||||
#define SEARCH_LOOPS 10000
|
||||
|
||||
static struct prio_tree_root root;
|
||||
static struct prio_tree_node nodes[NODES];
|
||||
static u32 queries[SEARCHES];
|
||||
|
||||
static struct rnd_state rnd;
|
||||
|
||||
static inline unsigned long
|
||||
search(unsigned long query, struct prio_tree_root *root)
|
||||
{
|
||||
struct prio_tree_iter iter;
|
||||
unsigned long results = 0;
|
||||
|
||||
prio_tree_iter_init(&iter, root, query, query);
|
||||
while (prio_tree_next(&iter))
|
||||
results++;
|
||||
return results;
|
||||
}
|
||||
|
||||
static void init(void)
|
||||
{
|
||||
int i;
|
||||
for (i = 0; i < NODES; i++) {
|
||||
u32 a = prandom32(&rnd), b = prandom32(&rnd);
|
||||
if (a <= b) {
|
||||
nodes[i].start = a;
|
||||
nodes[i].last = b;
|
||||
} else {
|
||||
nodes[i].start = b;
|
||||
nodes[i].last = a;
|
||||
}
|
||||
}
|
||||
for (i = 0; i < SEARCHES; i++)
|
||||
queries[i] = prandom32(&rnd);
|
||||
}
|
||||
|
||||
static int prio_tree_test_init(void)
|
||||
{
|
||||
int i, j;
|
||||
unsigned long results;
|
||||
cycles_t time1, time2, time;
|
||||
|
||||
printk(KERN_ALERT "prio tree insert/remove");
|
||||
|
||||
prandom32_seed(&rnd, 3141592653589793238ULL);
|
||||
INIT_PRIO_TREE_ROOT(&root);
|
||||
init();
|
||||
|
||||
time1 = get_cycles();
|
||||
|
||||
for (i = 0; i < PERF_LOOPS; i++) {
|
||||
for (j = 0; j < NODES; j++)
|
||||
prio_tree_insert(&root, nodes + j);
|
||||
for (j = 0; j < NODES; j++)
|
||||
prio_tree_remove(&root, nodes + j);
|
||||
}
|
||||
|
||||
time2 = get_cycles();
|
||||
time = time2 - time1;
|
||||
|
||||
time = div_u64(time, PERF_LOOPS);
|
||||
printk(" -> %llu cycles\n", (unsigned long long)time);
|
||||
|
||||
printk(KERN_ALERT "prio tree search");
|
||||
|
||||
for (j = 0; j < NODES; j++)
|
||||
prio_tree_insert(&root, nodes + j);
|
||||
|
||||
time1 = get_cycles();
|
||||
|
||||
results = 0;
|
||||
for (i = 0; i < SEARCH_LOOPS; i++)
|
||||
for (j = 0; j < SEARCHES; j++)
|
||||
results += search(queries[j], &root);
|
||||
|
||||
time2 = get_cycles();
|
||||
time = time2 - time1;
|
||||
|
||||
time = div_u64(time, SEARCH_LOOPS);
|
||||
results = div_u64(results, SEARCH_LOOPS);
|
||||
printk(" -> %llu cycles (%lu results)\n",
|
||||
(unsigned long long)time, results);
|
||||
|
||||
return -EAGAIN; /* Fail will directly unload the module */
|
||||
}
|
||||
|
||||
static void prio_tree_test_exit(void)
|
||||
{
|
||||
printk(KERN_ALERT "test exit\n");
|
||||
}
|
||||
|
||||
module_init(prio_tree_test_init)
|
||||
module_exit(prio_tree_test_exit)
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("Michel Lespinasse");
|
||||
MODULE_DESCRIPTION("Prio Tree test");
|
||||
Loading…
Reference in New Issue
Block a user