lib: Export interval_tree

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@chris-wilson.co.uk>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
[Acked for inclusion via drm/i915 by Andrew Morton.]
[danvet: switch to _GPL as per the mailing list discussion.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/lib/Kconfig b/lib/Kconfig
index 4771fb3f4da4deafdab8b26c76df9c0bec618300..334f7722a999232aa46b706d8cda61b57c854708 100644 (file)
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -331,6 +331,20 @@ 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 819ac51202c01006e105f91355d492db6bdd6eb6..4bff173fef0a916cd2dccd0f1c50d4f2acab6925 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1496,6 +1496,7 @@ 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 0cd7b68e1382dee93301898da70a6ca51c3d764e..2c6c1a42e1d2f748ad534958f99c64ae971dd31d 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -50,6 +50,7 @@ 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-$(CONFIG_DEBUG_LIST) += list_debug.o
@@ -156,8 +157,6 @@ lib-$(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 e6eb406f2d65dd3c4e22520239ec10afdd42dc30..f367f9ad544c3901a0ee5bcdfe451ac8b9b2aea3 100644 (file)
--- 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_GPL(interval_tree_insert);
+EXPORT_SYMBOL_GPL(interval_tree_remove);
+EXPORT_SYMBOL_GPL(interval_tree_iter_first);
+EXPORT_SYMBOL_GPL(interval_tree_iter_next);

diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
new file mode 100644 (file)
index 0000000..245900b
--- /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 (file)
index 245900b..0000000
--- 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");