[dpdk-dev] [PATCH 3/3] test scaling of HTM lock elision protecting rte_hash

[Roman Dementiev <roman.dementiev@intel.com>]

This patch adds a new auto-test for testing the scaling
of concurrent inserts into rte_hash when protected by
the normal spinlock vs. the spinlock with HTM lock
elision. The test also benchmarks single-threaded
access without any locks.

Signed-off-by: Roman Dementiev <roman.dementiev@intel.com>
---
 app/test/Makefile            |   1 +
 app/test/test_hash_scaling.c | 223 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 224 insertions(+)
 create mode 100644 app/test/test_hash_scaling.c

diff --git a/app/test/Makefile b/app/test/Makefile
index 3c777bf..6ffe539 100644
--- a/app/test/Makefile
+++ b/app/test/Makefile
@@ -83,6 +83,7 @@ SRCS-y += test_memcpy_perf.c
 
 SRCS-$(CONFIG_RTE_LIBRTE_HASH) += test_hash.c
 SRCS-$(CONFIG_RTE_LIBRTE_HASH) += test_hash_perf.c
+SRCS-$(CONFIG_RTE_LIBRTE_HASH) += test_hash_scaling.c
 
 SRCS-$(CONFIG_RTE_LIBRTE_LPM) += test_lpm.c
 SRCS-$(CONFIG_RTE_LIBRTE_LPM) += test_lpm6.c
diff --git a/app/test/test_hash_scaling.c b/app/test/test_hash_scaling.c
new file mode 100644
index 0000000..682ae94
--- /dev/null
+++ b/app/test/test_hash_scaling.c
@@ -0,0 +1,223 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <rte_cycles.h>
+#include <rte_hash.h>
+#include <rte_hash_crc.h>
+#include <rte_spinlock.h>
+#include <rte_launch.h>
+
+#include "test.h"
+
+/*
+ * Check condition and return an error if true. Assumes that "handle" is the
+ * name of the hash structure pointer to be freed.
+ */
+#define RETURN_IF_ERROR(cond, str, ...) do {				\
+	if (cond) {							\
+		printf("ERROR line %d: " str "\n", __LINE__,		\
+							##__VA_ARGS__);	\
+		if (handle)						\
+			rte_hash_free(handle);				\
+		return -1;						\
+	}								\
+} while (0)
+
+enum locking_mode_t {
+	NORMAL_LOCK,
+	LOCK_ELISION,
+	NULL_LOCK
+};
+
+struct {
+	uint32_t num_iterations;
+	struct rte_hash *h;
+	rte_spinlock_t *lock;
+	int locking_mode;
+} tbl_scaling_test_params;
+
+static rte_atomic64_t gcycles;
+
+static int test_hash_scaling_worker(__attribute__((unused)) void *arg)
+{
+	uint64_t i, key;
+	uint32_t thr_id = rte_sys_gettid();
+	uint64_t begin, cycles = 0;
+
+	switch (tbl_scaling_test_params.locking_mode) {
+
+	case NORMAL_LOCK:
+
+		for (i = 0; i < tbl_scaling_test_params.num_iterations; i++) {
+			/*	different threads get different keys because
+				we use the thread-id in the key computation
+			 */
+			key = rte_hash_crc(&i, sizeof(i), thr_id);
+			begin = rte_rdtsc_precise();
+			rte_spinlock_lock(tbl_scaling_test_params.lock);
+			rte_hash_add_key(tbl_scaling_test_params.h, &key);
+			rte_spinlock_unlock(tbl_scaling_test_params.lock);
+			cycles += rte_rdtsc_precise() - begin;
+		}
+		break;
+
+	case LOCK_ELISION:
+
+		for (i = 0; i < tbl_scaling_test_params.num_iterations; i++) {
+			key = rte_hash_crc(&i, sizeof(i), thr_id);
+			begin = rte_rdtsc_precise();
+			rte_spinlock_lock_tm(tbl_scaling_test_params.lock);
+			rte_hash_add_key(tbl_scaling_test_params.h, &key);
+			rte_spinlock_unlock_tm(tbl_scaling_test_params.lock);
+			cycles += rte_rdtsc_precise() - begin;
+		}
+		break;
+
+	default:
+
+		for (i = 0; i < tbl_scaling_test_params.num_iterations; i++) {
+			key = rte_hash_crc(&i, sizeof(i), thr_id);
+			begin = rte_rdtsc_precise();
+			rte_hash_add_key(tbl_scaling_test_params.h, &key);
+			cycles += rte_rdtsc_precise() - begin;
+		}
+	}
+
+	rte_atomic64_add(&gcycles, cycles);
+
+	return 0;
+}
+
+/*
+ * Do scalability perf tests.
+ */
+static int
+test_hash_scaling(int locking_mode)
+{
+	static unsigned calledCount =    1;
+	uint32_t num_iterations = 1024*1024;
+	uint64_t i, key;
+	struct rte_hash_parameters hash_params = {
+		.entries = num_iterations*2,
+		.bucket_entries = 16,
+		.key_len = sizeof(key),
+		.hash_func = rte_hash_crc,
+		.hash_func_init_val = 0,
+		.socket_id = rte_socket_id(),
+	};
+	struct rte_hash *handle;
+	char name[RTE_HASH_NAMESIZE];
+	rte_spinlock_t lock;
+
+	rte_spinlock_init(&lock);
+
+	snprintf(name, 32, "test%u", calledCount++);
+	hash_params.name = name;
+
+	handle = rte_hash_create(&hash_params);
+	RETURN_IF_ERROR(handle == NULL, "hash creation failed");
+
+	tbl_scaling_test_params.num_iterations =
+		num_iterations/rte_lcore_count();
+	tbl_scaling_test_params.h = handle;
+	tbl_scaling_test_params.lock = &lock;
+	tbl_scaling_test_params.locking_mode = locking_mode;
+
+	rte_atomic64_init(&gcycles);
+	rte_atomic64_clear(&gcycles);
+
+	/* fill up to initial size */
+	for (i = 0; i < num_iterations; i++) {
+		key = rte_hash_crc(&i, sizeof(i), 0xabcdabcd);
+		rte_hash_add_key(tbl_scaling_test_params.h, &key);
+	}
+
+	rte_eal_mp_remote_launch(test_hash_scaling_worker, NULL, CALL_MASTER);
+	rte_eal_mp_wait_lcore();
+
+	unsigned long long int cycles_per_operation =
+		rte_atomic64_read(&gcycles)/
+		(tbl_scaling_test_params.num_iterations*rte_lcore_count());
+	const char *lock_name;
+
+	switch (locking_mode) {
+	case NORMAL_LOCK:
+		lock_name = "normal spinlock";
+		break;
+	case LOCK_ELISION:
+		lock_name = "lock elision";
+		break;
+	default:
+		lock_name = "null lock";
+	}
+	printf("--------------------------------------------------------\n");
+	printf("Cores: %d; %s mode ->  cycles per operation: %llu\n",
+		rte_lcore_count(), lock_name, cycles_per_operation);
+	printf("--------------------------------------------------------\n");
+	/* CSV output */
+	printf(">>>%d,%s,%llu\n", rte_lcore_count(), lock_name,
+		cycles_per_operation);
+
+	rte_hash_free(handle);
+	return 0;
+}
+
+static int
+test_hash_scaling_main(void)
+{
+	int r = 0;
+
+	if (rte_lcore_count() == 1)
+		r = test_hash_scaling(NULL_LOCK);
+
+	if (r == 0)
+		r = test_hash_scaling(NORMAL_LOCK);
+
+	if (!rte_tm_supported()) {
+		printf("Hardware transactional memory (lock elision) is NOT supported\n");
+		return r;
+	}
+	printf("Hardware transactional memory (lock elision) is supported\n");
+
+	if (r == 0)
+		r = test_hash_scaling(LOCK_ELISION);
+
+	return r;
+}
+
+
+static struct test_command hash_scaling_cmd = {
+	.command = "hash_scaling_autotest",
+	.callback = test_hash_scaling_main,
+};
+REGISTER_TEST_COMMAND(hash_scaling_cmd);
-- 
1.9.5.msysgit.0

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