The patch titled
Subject: rbtree: performance and correctness test
has been added to the -mm tree. Its filename is
rbtree-performance-and-correctness-test.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Michel Lespinasse <walken@xxxxxxxxxx>
Subject: rbtree: performance and correctness test
This small module helps measure the performance of rbtree insert and
erase.
Additionally, we run a few correctness tests to check that the rbtrees
have all desired properties:
- contains the right number of nodes in the order desired,
- never two consecutive red nodes on any path,
- all paths to leaf nodes have the same number of black nodes,
- root node is black
Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Daniel Santos <daniel.santos@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/Kconfig.debug | 7 ++
lib/Makefile | 2
lib/rbtree_test.c | 135 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 144 insertions(+)
diff -puN lib/Kconfig.debug~rbtree-performance-and-correctness-test lib/Kconfig.debug
--- a/lib/Kconfig.debug~rbtree-performance-and-correctness-test
+++ a/lib/Kconfig.debug
@@ -1178,6 +1178,13 @@ config LATENCYTOP
source mm/Kconfig.debug
source kernel/trace/Kconfig
+config RBTREE_TEST
+ tristate "Red-Black tree test"
+ depends on m && DEBUG_KERNEL
+ help
+ A benchmark measuring the performance of the rbtree library.
+ Also includes rbtree invariant checks.
+
config PROVIDE_OHCI1394_DMA_INIT
bool "Remote debugging over FireWire early on boot"
depends on PCI && X86
diff -puN lib/Makefile~rbtree-performance-and-correctness-test lib/Makefile
--- a/lib/Makefile~rbtree-performance-and-correctness-test
+++ a/lib/Makefile
@@ -135,6 +135,8 @@ $(foreach file, $(libfdt_files), \
$(eval CFLAGS_$(file) = -I$(src)/../scripts/dtc/libfdt))
lib-$(CONFIG_LIBFDT) += $(libfdt_files)
+obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o
+
hostprogs-y := gen_crc32table
clean-files := crc32table.h
diff -puN /dev/null lib/rbtree_test.c
--- /dev/null
+++ a/lib/rbtree_test.c
@@ -0,0 +1,135 @@
+#include <linux/module.h>
+#include <linux/rbtree.h>
+#include <linux/random.h>
+#include <asm/timex.h>
+
+#define NODES 100
+#define PERF_LOOPS 100000
+#define CHECK_LOOPS 100
+
+struct test_node {
+ struct rb_node rb;
+ u32 key;
+};
+
+static struct rb_root root = RB_ROOT;
+static struct test_node nodes[NODES];
+
+static struct rnd_state rnd;
+
+static void insert(struct test_node *node, struct rb_root *root)
+{
+ struct rb_node **new = &root->rb_node, *parent = NULL;
+
+ while (*new) {
+ parent = *new;
+ if (node->key < rb_entry(parent, struct test_node, rb)->key)
+ new = &parent->rb_left;
+ else
+ new = &parent->rb_right;
+ }
+
+ rb_link_node(&node->rb, parent, new);
+ rb_insert_color(&node->rb, root);
+}
+
+static inline void erase(struct test_node *node, struct rb_root *root)
+{
+ rb_erase(&node->rb, root);
+}
+
+static void init(void)
+{
+ int i;
+ for (i = 0; i < NODES; i++)
+ nodes[i].key = prandom32(&rnd);
+}
+
+static bool is_red(struct rb_node *rb)
+{
+ return !(rb->__rb_parent_color & 1);
+}
+
+static int black_path_count(struct rb_node *rb)
+{
+ int count;
+ for (count = 0; rb; rb = rb_parent(rb))
+ count += !is_red(rb);
+ return count;
+}
+
+static void check(int nr_nodes)
+{
+ struct rb_node *rb;
+ int count = 0;
+ int blacks;
+ u32 prev_key = 0;
+
+ for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
+ struct test_node *node = rb_entry(rb, struct test_node, rb);
+ WARN_ON_ONCE(node->key < prev_key);
+ WARN_ON_ONCE(is_red(rb) &&
+ (!rb_parent(rb) || is_red(rb_parent(rb))));
+ if (!count)
+ blacks = black_path_count(rb);
+ else
+ WARN_ON_ONCE((!rb->rb_left || !rb->rb_right) &&
+ blacks != black_path_count(rb));
+ prev_key = node->key;
+ count++;
+ }
+ WARN_ON_ONCE(count != nr_nodes);
+}
+
+static int rbtree_test_init(void)
+{
+ int i, j;
+ cycles_t time1, time2, time;
+
+ printk(KERN_ALERT "rbtree testing");
+
+ prandom32_seed(&rnd, 3141592653589793238);
+ init();
+
+ time1 = get_cycles();
+
+ for (i = 0; i < PERF_LOOPS; i++) {
+ for (j = 0; j < NODES; j++)
+ insert(nodes + j, &root);
+ for (j = 0; j < NODES; j++)
+ erase(nodes + j, &root);
+ }
+
+ time2 = get_cycles();
+ time = time2 - time1;
+
+ time = div_u64(time, PERF_LOOPS);
+ printk(" -> %llu cycles\n", time);
+
+ for (i = 0; i < CHECK_LOOPS; i++) {
+ init();
+ for (j = 0; j < NODES; j++) {
+ check(j);
+ insert(nodes + j, &root);
+ }
+ for (j = 0; j < NODES; j++) {
+ check(NODES - j);
+ erase(nodes + j, &root);
+ }
+ check(0);
+ }
+
+ return -EAGAIN; /* Fail will directly unload the module */
+}
+
+static void rbtree_test_exit(void)
+{
+ printk(KERN_ALERT "test exit\n");
+}
+
+module_init(rbtree_test_init)
+module_exit(rbtree_test_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michel Lespinasse");
+MODULE_DESCRIPTION("Red Black Tree test");
_
Subject: Subject: rbtree: performance and correctness test
Patches currently in -mm which might be from walken@xxxxxxxxxx are
slab-do-not-call-compound_head-in-page_get_cache.patch
rbtree-reference-documentation-rbtreetxt-for-usage-instructions.patch
rbtree-empty-nodes-have-no-color.patch
rbtree-fix-incorrect-rbtree-node-insertion-in-fs-proc-proc_sysctlc.patch
rbtree-move-some-implementation-details-from-rbtreeh-to-rbtreec.patch
rbtree-performance-and-correctness-test.patch
rbtree-break-out-of-rb_insert_color-loop-after-tree-rotation.patch
rbtree-adjust-root-color-in-rb_insert_color-only-when-necessary.patch
rbtree-low-level-optimizations-in-rb_insert_color.patch
rbtree-adjust-node-color-in-__rb_erase_color-only-when-necessary.patch
rbtree-optimize-case-selection-logic-in-__rb_erase_color.patch
rbtree-low-level-optimizations-in-__rb_erase_color.patch
rbtree-coding-style-adjustments.patch
--
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