From: Phil Yang Date: Fri, 18 Oct 2019 11:21:29 +0000 (+0800) Subject: test/atomic: add 128-bit atomic compare exchange test X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=fa3253c534b17ec9ef59f2bcbfeb51f01d0c1d96;p=dpdk.git test/atomic: add 128-bit atomic compare exchange test Add 128-bit atomic compare and swap test for aarch64 and x86_64. Extend the test iteration from 10 thousand to 1 million times to test the stability of the atomic APIs. Signed-off-by: Phil Yang Reviewed-by: Honnappa Nagarahalli Acked-by: Gage Eads Acked-by: Jerin Jacob Tested-by: Jerin Jacob --- diff --git a/app/test/test_atomic.c b/app/test/test_atomic.c index 43be30ec0b..2df950694b 100644 --- a/app/test/test_atomic.c +++ b/app/test/test_atomic.c @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: BSD-3-Clause * Copyright(c) 2010-2014 Intel Corporation + * Copyright(c) 2019 Arm Limited */ #include @@ -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 "128-bit compare and swap" (aarch64 and x86_64 only) + * + * - Initialize 128-bit atomic variables to zero. + * + * - Invoke ``test_atomic128_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 N 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_atomic128_cmp_exchange + * API. It calls rte_atomic128_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 N 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("128-bit 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("128-bit compare and swap failed\n"); + return -1; + } +#endif + return 0; }