[PATCH] lib: Export interval_tree
From: Chris Wilson
Date: Sun Jan 26 2014 - 07:41:55 EST
lib/interval_tree.c provides a simple interface for an interval-tree
(an augmented red-black tree) but is only built when testing the generic
macros for building interval-trees. For drivers with modest needs,
export the simple interval-tree library as is.
v2: Lots of help from Michel Lespinasse to only compile the code
as required:
- make INTERVAL_TREE a config option
- make INTERVAL_TREE_TEST select the library functions
and sanitize the filenames & Makefile
- prepare interval_tree for being built as a module if required
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Note for maintainers, this is being proposed for use by i915.ko, so it
may make the most sense to merge it via the drm/i915 tree in the next
cycle.
---
lib/Kconfig | 14 ++++++
lib/Kconfig.debug | 1 +
lib/Makefile | 3 +-
lib/interval_tree.c | 6 +++
lib/interval_tree_test.c | 106 ++++++++++++++++++++++++++++++++++++++++++
lib/interval_tree_test_main.c | 106 ------------------------------------------
6 files changed, 128 insertions(+), 108 deletions(-)
create mode 100644 lib/interval_tree_test.c
delete mode 100644 lib/interval_tree_test_main.c
diff --git a/lib/Kconfig b/lib/Kconfig
index 991c98bc4a3f..04270aae4b60 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -322,6 +322,20 @@ config TEXTSEARCH_FSM
config BTREE
boolean
+config INTERVAL_TREE
+ boolean
+ help
+ Simple, embeddable, interval-tree. Can find the start of an
+ overlapping range in log(n) time and then iterate over all
+ overlapping nodes. The algorithm is implemented as an
+ augmented rbtree.
+
+ See:
+
+ Documentation/rbtree.txt
+
+ for more information.
+
config ASSOCIATIVE_ARRAY
bool
help
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index db25707aa41b..a29e9b84f102 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1478,6 +1478,7 @@ config RBTREE_TEST
config INTERVAL_TREE_TEST
tristate "Interval tree test"
depends on m && DEBUG_KERNEL
+ select INTERVAL_TREE
help
A benchmark measuring the performance of the interval tree library
diff --git a/lib/Makefile b/lib/Makefile
index a459c31e8c6b..fc04948548ad 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -47,6 +47,7 @@ CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS))
obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
obj-$(CONFIG_BTREE) += btree.o
+obj-$(CONFIG_INTERVAL_TREE) += interval_tree.o
obj-$(CONFIG_ASSOCIATIVE_ARRAY) += assoc_array.o
obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
obj-$(CONFIG_DEBUG_LIST) += list_debug.o
@@ -152,8 +153,6 @@ lib-$(CONFIG_LIBFDT) += $(libfdt_files)
obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o
obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o
-interval_tree_test-objs := interval_tree_test_main.o interval_tree.o
-
obj-$(CONFIG_PERCPU_TEST) += percpu_test.o
obj-$(CONFIG_ASN1) += asn1_decoder.o
diff --git a/lib/interval_tree.c b/lib/interval_tree.c
index e6eb406f2d65..e4109f624e51 100644
--- a/lib/interval_tree.c
+++ b/lib/interval_tree.c
@@ -1,6 +1,7 @@
#include <linux/init.h>
#include <linux/interval_tree.h>
#include <linux/interval_tree_generic.h>
+#include <linux/module.h>
#define START(node) ((node)->start)
#define LAST(node) ((node)->last)
@@ -8,3 +9,8 @@
INTERVAL_TREE_DEFINE(struct interval_tree_node, rb,
unsigned long, __subtree_last,
START, LAST,, interval_tree)
+
+EXPORT_SYMBOL(interval_tree_insert);
+EXPORT_SYMBOL(interval_tree_remove);
+EXPORT_SYMBOL(interval_tree_iter_first);
+EXPORT_SYMBOL(interval_tree_iter_next);
diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
new file mode 100644
index 000000000000..245900b98c8e
--- /dev/null
+++ b/lib/interval_tree_test.c
@@ -0,0 +1,106 @@
+#include <linux/module.h>
+#include <linux/interval_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 rb_root root = RB_ROOT;
+static struct interval_tree_node nodes[NODES];
+static u32 queries[SEARCHES];
+
+static struct rnd_state rnd;
+
+static inline unsigned long
+search(unsigned long query, struct rb_root *root)
+{
+ struct interval_tree_node *node;
+ unsigned long results = 0;
+
+ for (node = interval_tree_iter_first(root, query, query); node;
+ node = interval_tree_iter_next(node, query, query))
+ results++;
+ return results;
+}
+
+static void init(void)
+{
+ int i;
+ for (i = 0; i < NODES; i++) {
+ u32 a = prandom_u32_state(&rnd);
+ u32 b = prandom_u32_state(&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] = prandom_u32_state(&rnd);
+}
+
+static int interval_tree_test_init(void)
+{
+ int i, j;
+ unsigned long results;
+ cycles_t time1, time2, time;
+
+ printk(KERN_ALERT "interval tree insert/remove");
+
+ prandom_seed_state(&rnd, 3141592653589793238ULL);
+ init();
+
+ time1 = get_cycles();
+
+ for (i = 0; i < PERF_LOOPS; i++) {
+ for (j = 0; j < NODES; j++)
+ interval_tree_insert(nodes + j, &root);
+ for (j = 0; j < NODES; j++)
+ interval_tree_remove(nodes + j, &root);
+ }
+
+ time2 = get_cycles();
+ time = time2 - time1;
+
+ time = div_u64(time, PERF_LOOPS);
+ printk(" -> %llu cycles\n", (unsigned long long)time);
+
+ printk(KERN_ALERT "interval tree search");
+
+ for (j = 0; j < NODES; j++)
+ interval_tree_insert(nodes + j, &root);
+
+ 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 interval_tree_test_exit(void)
+{
+ printk(KERN_ALERT "test exit\n");
+}
+
+module_init(interval_tree_test_init)
+module_exit(interval_tree_test_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michel Lespinasse");
+MODULE_DESCRIPTION("Interval Tree test");
diff --git a/lib/interval_tree_test_main.c b/lib/interval_tree_test_main.c
deleted file mode 100644
index 245900b98c8e..000000000000
--- a/lib/interval_tree_test_main.c
+++ /dev/null
@@ -1,106 +0,0 @@
-#include <linux/module.h>
-#include <linux/interval_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 rb_root root = RB_ROOT;
-static struct interval_tree_node nodes[NODES];
-static u32 queries[SEARCHES];
-
-static struct rnd_state rnd;
-
-static inline unsigned long
-search(unsigned long query, struct rb_root *root)
-{
- struct interval_tree_node *node;
- unsigned long results = 0;
-
- for (node = interval_tree_iter_first(root, query, query); node;
- node = interval_tree_iter_next(node, query, query))
- results++;
- return results;
-}
-
-static void init(void)
-{
- int i;
- for (i = 0; i < NODES; i++) {
- u32 a = prandom_u32_state(&rnd);
- u32 b = prandom_u32_state(&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] = prandom_u32_state(&rnd);
-}
-
-static int interval_tree_test_init(void)
-{
- int i, j;
- unsigned long results;
- cycles_t time1, time2, time;
-
- printk(KERN_ALERT "interval tree insert/remove");
-
- prandom_seed_state(&rnd, 3141592653589793238ULL);
- init();
-
- time1 = get_cycles();
-
- for (i = 0; i < PERF_LOOPS; i++) {
- for (j = 0; j < NODES; j++)
- interval_tree_insert(nodes + j, &root);
- for (j = 0; j < NODES; j++)
- interval_tree_remove(nodes + j, &root);
- }
-
- time2 = get_cycles();
- time = time2 - time1;
-
- time = div_u64(time, PERF_LOOPS);
- printk(" -> %llu cycles\n", (unsigned long long)time);
-
- printk(KERN_ALERT "interval tree search");
-
- for (j = 0; j < NODES; j++)
- interval_tree_insert(nodes + j, &root);
-
- 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 interval_tree_test_exit(void)
-{
- printk(KERN_ALERT "test exit\n");
-}
-
-module_init(interval_tree_test_init)
-module_exit(interval_tree_test_exit)
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Michel Lespinasse");
-MODULE_DESCRIPTION("Interval Tree test");
--
1.8.5.3
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