[PATCH v3 08/33] radix tree test suite: benchmark for iterator

Matthew Wilcox
2016-11-28T20:14:25Z

From: Konstantin Khlebnikov <koct9i@gmail.com>

This adds simple benchmark for iterator similar to one I've used for
commit 78c1d78 ("radix-tree: introduce bit-optimized iterator")

Building with make BENCHMARK=1 set radix tree order to 6, this allows
to get performance comparable to in kernel performance.

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
tools/testing/radix-tree/Makefile | 6 +-
tools/testing/radix-tree/benchmark.c | 98 +++++++++++++++++++++++++++++++++
tools/testing/radix-tree/linux/kernel.h | 4 ++
tools/testing/radix-tree/main.c | 2 +
tools/testing/radix-tree/test.h | 1 +
5 files changed, 110 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/radix-tree/benchmark.c

diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile
index 3c338dc..08283a8 100644
--- a/tools/testing/radix-tree/Makefile
+++ b/tools/testing/radix-tree/Makefile
@@ -4,7 +4,11 @@ LDFLAGS += -lpthread -lurcu
TARGETS = main
OFILES = main.o radix-tree.o linux.o test.o tag_check.o find_next_bit.o \
regression1.o regression2.o regression3.o multiorder.o \
- iteration_check.o
+ iteration_check.o benchmark.o
+
+ifdef BENCHMARK
+ CFLAGS += -DBENCHMARK=1
+endif

targets: $(TARGETS)

diff --git a/tools/testing/radix-tree/benchmark.c b/tools/testing/radix-tree/benchmark.c
new file mode 100644
index 0000000..215ca86
--- /dev/null
+++ b/tools/testing/radix-tree/benchmark.c
@@ -0,0 +1,98 @@
+/*
+ * benchmark.c:
+ * Author: Konstantin Khlebnikov <koct9i@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/radix-tree.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <time.h>
+#include "test.h"
+
+#define NSEC_PER_SEC 1000000000L
+
+static long long benchmark_iter(struct radix_tree_root *root, bool tagged)
+{
+ volatile unsigned long sink = 0;
+ struct radix_tree_iter iter;
+ struct timespec start, finish;
+ long long nsec;
+ int l, loops = 1;
+ void **slot;
+
+#ifdef BENCHMARK
+again:
+#endif
+ clock_gettime(CLOCK_MONOTONIC, &start);
+ for (l = 0; l < loops; l++) {
+ if (tagged) {
+ radix_tree_for_each_tagged(slot, root, &iter, 0, 0)
+ sink ^= (unsigned long)slot;
+ } else {
+ radix_tree_for_each_slot(slot, root, &iter, 0)
+ sink ^= (unsigned long)slot;
+ }
+ }
+ clock_gettime(CLOCK_MONOTONIC, &finish);
+
+ nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC +
+ (finish.tv_nsec - start.tv_nsec);
+
+#ifdef BENCHMARK
+ if (loops == 1 && nsec * 5 < NSEC_PER_SEC) {
+ loops = NSEC_PER_SEC / nsec / 4 + 1;
+ goto again;
+ }
+#endif
+
+ nsec /= loops;
+ return nsec;
+}
+
+static void benchmark_size(unsigned long size, unsigned long step, int order)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ long long normal, tagged;
+ unsigned long index;
+
+ for (index = 0 ; index < size ; index += step) {
+ item_insert_order(&tree, index, order);
+ radix_tree_tag_set(&tree, index, 0);
+ }
+
+ tagged = benchmark_iter(&tree, true);
+ normal = benchmark_iter(&tree, false);
+
+ printf("Size %ld, step %6ld, order %d tagged %10lld ns, normal %10lld ns\n",
+ size, step, order, tagged, normal);
+
+ item_kill_tree(&tree);
+ rcu_barrier();
+}
+
+void benchmark(void)
+{
+ unsigned long size[] = {1 << 10, 1 << 20, 0};
+ unsigned long step[] = {1, 2, 7, 15, 63, 64, 65,
+ 128, 256, 512, 12345, 0};
+ int c, s;
+
+ printf("starting benchmarks\n");
+ printf("RADIX_TREE_MAP_SHIFT = %d\n", RADIX_TREE_MAP_SHIFT);
+
+ for (c = 0; size[c]; c++)
+ for (s = 0; step[s]; s++)
+ benchmark_size(size[c], step[s], 0);
+
+ for (c = 0; size[c]; c++)
+ for (s = 0; step[s]; s++)
+ benchmark_size(size[c], step[s] << 9, 9);
+}
diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index be98a47..dbe4b92 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -10,7 +10,11 @@
#include "../../include/linux/compiler.h"
#include "../../../include/linux/kconfig.h"

+#ifdef BENCHMARK
+#define RADIX_TREE_MAP_SHIFT 6
+#else
#define RADIX_TREE_MAP_SHIFT 3
+#endif

#ifndef NULL
#define NULL 0
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 2eb6949..f1d1e3b 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -352,6 +352,8 @@ int main(int argc, char **argv)
/* Free any remaining preallocated nodes */
radix_tree_cpu_dead(0);

+ benchmark();
+
sleep(1);
printf("after sleep(1): %d allocated, preempt %d\n",
nr_allocated, preempt_count);
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index 5d2fad0..215ab77 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -28,6 +28,7 @@ void item_kill_tree(struct radix_tree_root *root);
void tag_check(void);
void multiorder_checks(void);
void iteration_test(void);
+void benchmark(void);

struct item *
item_tag_set(struct radix_tree_root *root, unsigned long index, int tag);
--
2.10.2