GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

radix-tree: add radix_tree_join

Browse source 
This new function allows for the replacement of many smaller entries in
the radix tree with one larger multiorder entry.  From the point of view
of an RCU walker, they may see a mixture of the smaller entries and the
large entry during the same walk, but they will never see NULL for an
index which was populated before the join.

Link: http://lkml.kernel.org/r/1480369871-5271-58-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox 2016-12-14 15:08:58 -08:00 • committed by Linus Torvalds
parent 268f42de71
commit 175542f575
3 changed files with 217 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

58
tools/testing/radix-tree/multiorder.c
View file

@ -332,6 +332,63 @@ void multiorder_tagged_iteration(void)
item_kill_tree(&tree);
}
static void __multiorder_join(unsigned long index,
unsigned order1, unsigned order2)
{
unsigned long loc;
void *item, *item2 = item_create(index + 1, order1);
RADIX_TREE(tree, GFP_KERNEL);
item_insert_order(&tree, index, order2);
item = radix_tree_lookup(&tree, index);
radix_tree_join(&tree, index + 1, order1, item2);
loc = find_item(&tree, item);
if (loc == -1)
free(item);
item = radix_tree_lookup(&tree, index + 1);
assert(item == item2);
item_kill_tree(&tree);
}
static void __multiorder_join2(unsigned order1, unsigned order2)
{
RADIX_TREE(tree, GFP_KERNEL);
struct radix_tree_node *node;
void *item1 = item_create(0, order1);
void *item2;
item_insert_order(&tree, 0, order2);
radix_tree_insert(&tree, 1 << order2, (void *)0x12UL);
item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
assert(item2 == (void *)0x12UL);
assert(node->exceptional == 1);
radix_tree_join(&tree, 0, order1, item1);
item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
assert(item2 == item1);
assert(node->exceptional == 0);
item_kill_tree(&tree);
}
static void multiorder_join(void)
{
int i, j, idx;
for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
__multiorder_join(idx, i, j);
}
}
}
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
__multiorder_join2(i, j);
}
}
}
void multiorder_checks(void)
{
int i;
@ -349,4 +406,5 @@ void multiorder_checks(void)
multiorder_tag_tests();
multiorder_iteration();
multiorder_tagged_iteration();
multiorder_join();
}