[v8,2/3] test/atomic: add 128b compare and swap test
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Commit Message
From: Phil Yang <phil.yang@arm.com>
Add 128b atomic compare and swap test for aarch64 and x86_64.
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
Tested-by: Jerin Jacob <jerinj@marvell.com>
---
app/test/test_atomic.c | 125 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 123 insertions(+), 2 deletions(-)
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2010-2014 Intel Corporation
+ * Copyright(c) 2019 Arm Limited
*/
#include <stdio.h>
@@ -20,7 +21,7 @@
* Atomic Variables
* ================
*
- * - The main test function performs three subtests. The first test
+ * - The main test function performs four subtests. The first test
* checks that the usual inc/dec/add/sub functions are working
* correctly:
*
@@ -61,11 +62,27 @@
* atomic_sub(&count, tmp+1);
*
* - At the end of the test, the *count* value must be 0.
+ *
+ * - Test "128b compare and swap" (aarch64 and x86_64 only)
+ *
+ * - Initialize 128-bit atomic variables to zero.
+ *
+ * - Invoke ``test_atomici128_cmp_exchange()`` on each lcore. Before doing
+ * anything else, the cores are waiting a synchro. Each lcore does
+ * these compare and swap (CAS) operations several times::
+ *
+ * Acquired CAS update counter.val[0] + 2; counter.val[1] + 1;
+ * Released CAS update counter.val[0] + 2; counter.val[1] + 1;
+ * Acquired_Released CAS update counter.val[0] + 2; counter.val[1] + 1;
+ * Relaxed CAS update counter.val[0] + 2; counter.val[1] + 1;
+ *
+ * - At the end of the test, the *count128* first 64-bit value and
+ * second 64-bit value differ by the total iterations.
*/
#define NUM_ATOMIC_TYPES 3
-#define N 10000
+#define N 1000000
static rte_atomic16_t a16;
static rte_atomic32_t a32;
@@ -216,6 +233,78 @@ test_atomic_dec_and_test(__attribute__((unused)) void *arg)
return 0;
}
+#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_ARM64)
+static rte_int128_t count128;
+
+/*
+ * rte_atomic128_cmp_exchange() should update a 128 bits counter's first 64
+ * bits by 2 and the second 64 bits by 1 in this test. It should return true
+ * if the compare exchange operation is successful.
+ * This test repeats 128 bits compare and swap operations 10K rounds. In each
+ * iteration it runs compare and swap operation with different memory models.
+ */
+static int
+test_atomic128_cmp_exchange(__attribute__((unused)) void *arg)
+{
+ rte_int128_t expected;
+ int success;
+ unsigned int i;
+
+ while (rte_atomic32_read(&synchro) == 0)
+ ;
+
+ expected = count128;
+
+ for (i = 0; i < N; i++) {
+ do {
+ rte_int128_t desired;
+
+ desired.val[0] = expected.val[0] + 2;
+ desired.val[1] = expected.val[1] + 1;
+
+ success = rte_atomic128_cmp_exchange(&count128,
+ &expected, &desired, 1,
+ __ATOMIC_ACQUIRE, __ATOMIC_RELAXED);
+ } while (success == 0);
+
+ do {
+ rte_int128_t desired;
+
+ desired.val[0] = expected.val[0] + 2;
+ desired.val[1] = expected.val[1] + 1;
+
+ success = rte_atomic128_cmp_exchange(&count128,
+ &expected, &desired, 1,
+ __ATOMIC_RELEASE, __ATOMIC_RELAXED);
+ } while (success == 0);
+
+ do {
+ rte_int128_t desired;
+
+ desired.val[0] = expected.val[0] + 2;
+ desired.val[1] = expected.val[1] + 1;
+
+ success = rte_atomic128_cmp_exchange(&count128,
+ &expected, &desired, 1,
+ __ATOMIC_ACQ_REL, __ATOMIC_RELAXED);
+ } while (success == 0);
+
+ do {
+ rte_int128_t desired;
+
+ desired.val[0] = expected.val[0] + 2;
+ desired.val[1] = expected.val[1] + 1;
+
+ success = rte_atomic128_cmp_exchange(&count128,
+ &expected, &desired, 1,
+ __ATOMIC_RELAXED, __ATOMIC_RELAXED);
+ } while (success == 0);
+ }
+
+ return 0;
+}
+#endif
+
static int
test_atomic(void)
{
@@ -340,6 +429,38 @@ test_atomic(void)
return -1;
}
+#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_ARM64)
+ /*
+ * This case tests the functionality of rte_atomic128b_cmp_exchange
+ * API. It calls rte_atomic128b_cmp_exchange with four kinds of memory
+ * models successively on each slave core. Once each 128-bit atomic
+ * compare and swap operation is successful, it updates the global
+ * 128-bit counter by 2 for the first 64-bit and 1 for the second
+ * 64-bit. Each slave core iterates this test 10K times.
+ * At the end of test, verify whether the first 64-bits of the 128-bit
+ * counter and the second 64bits is differ by the total iterations. If
+ * it is, the test passes.
+ */
+ printf("128b compare and swap test\n");
+ uint64_t iterations = 0;
+
+ rte_atomic32_clear(&synchro);
+ count128.val[0] = 0;
+ count128.val[1] = 0;
+
+ rte_eal_mp_remote_launch(test_atomic128_cmp_exchange, NULL,
+ SKIP_MASTER);
+ rte_atomic32_set(&synchro, 1);
+ rte_eal_mp_wait_lcore();
+ rte_atomic32_clear(&synchro);
+
+ iterations = count128.val[0] - count128.val[1];
+ if (iterations != 4*N*(rte_lcore_count()-1)) {
+ printf("128b compare and swap failed\n");
+ return -1;
+ }
+#endif
+
return 0;
}