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authorDavidlohr Bueso <dave@stgolabs.net>2017-07-11 01:51:49 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-11 02:32:35 +0300
commita8ec14d4f6aa8e245efacc992c8ee6ea0464ce2a (patch)
treeeb6eaca9080f9cbdb6d17af2ebf64c80175daa52 /lib
parenta54dae0338b7f01eb0f9c7571fb9b74f791d1c6b (diff)
downloadlinux-a8ec14d4f6aa8e245efacc992c8ee6ea0464ce2a.tar.xz
lib/interval_tree_test.c: allow users to limit scope of endpoint
Add a 'max_endpoint' parameter such that users may easily limit the size of the intervals that are randomly generated. Link: http://lkml.kernel.org/r/20170518174936.20265-4-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/interval_tree_test.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
index 1093f0496d5e..0fef6364a958 100644
--- a/lib/interval_tree_test.c
+++ b/lib/interval_tree_test.c
@@ -16,6 +16,7 @@ __param(int, perf_loops, 100000, "Number of iterations modifying the tree");
__param(int, nsearches, 100, "Number of searches to the interval tree");
__param(int, search_loops, 10000, "Number of iterations searching the tree");
+__param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
static struct rb_root root = RB_ROOT;
static struct interval_tree_node *nodes = NULL;
@@ -40,18 +41,20 @@ static void init(void)
int i;
for (i = 0; i < nnodes; 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;
- }
+ u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
+ u32 a = (prandom_u32_state(&rnd) >> 4) % b;
+
+ nodes[i].start = a;
+ nodes[i].last = b;
}
+
+ /*
+ * Limit the search scope to what the user defined.
+ * Otherwise we are merely measuring empty walks,
+ * which is pointless.
+ */
for (i = 0; i < nsearches; i++)
- queries[i] = prandom_u32_state(&rnd);
+ queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
}
static int interval_tree_test_init(void)