From e79f49b4e2ccf737e9bf660bd56221994a94d150 Mon Sep 17 00:00:00 2001 From: David Christensen Date: Wed, 6 Nov 2019 13:18:35 -0800 Subject: [PATCH] test/atomic: add atomic 16/32/64-bit exchanges test The test works by creating a token comprised of random data and a CRC8 value, using the rte_atomicXX_exchange to exchange the new token for a previously generated token, and then verifying that the exchanged data is intact (i.e. the CRC8 is still correct for the data). Signed-off-by: David Christensen Acked-by: David Marchand --- app/test/test_atomic.c | 175 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 171 insertions(+), 4 deletions(-) diff --git a/app/test/test_atomic.c b/app/test/test_atomic.c index 2df950694b..de3030d221 100644 --- a/app/test/test_atomic.c +++ b/app/test/test_atomic.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include @@ -14,6 +15,8 @@ #include #include #include +#include +#include #include "test.h" @@ -21,7 +24,7 @@ * Atomic Variables * ================ * - * - The main test function performs four subtests. The first test + * - The main test function performs several subtests. The first * checks that the usual inc/dec/add/sub functions are working * correctly: * @@ -34,7 +37,7 @@ * - The function checks that once all lcores finish their function, * the value of the atomic variables are still the same. * - * - The second test verifies the behavior of "test and set" functions. + * - Test "test and set" functions. * * - Initialize 16-bit, 32-bit and 64-bit atomic variables to zero. * @@ -48,7 +51,7 @@ * - The main function checks that the atomic counter was incremented * twice only (one for 16-bit, one for 32-bit and one for 64-bit values). * - * - Test "add/sub and return" + * - Test "add/sub and return" functions * * - Initialize 16-bit, 32-bit and 64-bit atomic variables to zero. * @@ -78,6 +81,20 @@ * * - At the end of the test, the *count128* first 64-bit value and * second 64-bit value differ by the total iterations. + * + * - Test "atomic exchange" functions + * + * - Create a 64 bit token that can be tested for data integrity + * + * - Invoke ``test_atomic_exchange`` on each lcore. Before doing + * anything else, the cores wait for a synchronization event. + * Each core then does the follwoing for N iterations: + * + * Generate a new token with a data integrity check + * Exchange the new token for previously generated token + * Increment a counter if a corrupt token was received + * + * - At the end of the test, the number of corrupted tokens must be 0. */ #define NUM_ATOMIC_TYPES 3 @@ -305,6 +322,125 @@ test_atomic128_cmp_exchange(__attribute__((unused)) void *arg) } #endif +/* + * Helper definitions/variables/functions for + * atomic exchange tests + */ +typedef union { + uint16_t u16; + uint8_t u8[2]; +} test16_t; + +typedef union { + uint32_t u32; + uint16_t u16[2]; + uint8_t u8[4]; +} test32_t; + +typedef union { + uint64_t u64; + uint32_t u32[2]; + uint16_t u16[4]; + uint8_t u8[8]; +} test64_t; + +const uint8_t CRC8_POLY = 0x91; +uint8_t crc8_table[256]; + +volatile uint16_t token16; +volatile uint32_t token32; +volatile uint64_t token64; + +static void +build_crc8_table(void) +{ + uint8_t val; + int i, j; + + for (i = 0; i < 256; i++) { + val = i; + for (j = 0; j < 8; j++) { + if (val & 1) + val ^= CRC8_POLY; + val >>= 1; + } + crc8_table[i] = val; + } +} + +static uint8_t +get_crc8(uint8_t *message, int length) +{ + uint8_t crc = 0; + int i; + + for (i = 0; i < length; i++) + crc = crc8_table[crc ^ message[i]]; + return crc; +} + +/* + * The atomic exchange test sets up a token in memory and + * then spins up multiple lcores whose job is to generate + * new tokens, exchange that new token for the old one held + * in memory, and then verify that the old token is still + * valid (i.e. the exchange did not corrupt the token). + * + * A token is made up of random data and 8 bits of crc + * covering that random data. The following is an example + * of a 64bit token. + * + * +------------+------------+ + * | 63 56 | 55 0 | + * +------------+------------+ + * | CRC8 | Data | + * +------------+------------+ + */ +static int +test_atomic_exchange(__attribute__((unused)) void *arg) +{ + int i; + test16_t nt16, ot16; /* new token, old token */ + test32_t nt32, ot32; + test64_t nt64, ot64; + + /* Wait until all of the other threads have been dispatched */ + while (rte_atomic32_read(&synchro) == 0) + ; + + /* + * Let the battle begin! Every thread attempts to steal the current + * token with an atomic exchange operation and install its own newly + * generated token. If the old token is valid (i.e. it has the + * appropriate crc32 hash for the data) then the test iteration has + * passed. If the token is invalid, increment the counter. + */ + for (i = 0; i < N; i++) { + + /* Test 64bit Atomic Exchange */ + nt64.u64 = rte_rand(); + nt64.u8[7] = get_crc8(&nt64.u8[0], sizeof(nt64) - 1); + ot64.u64 = rte_atomic64_exchange(&token64, nt64.u64); + if (ot64.u8[7] != get_crc8(&ot64.u8[0], sizeof(ot64) - 1)) + rte_atomic64_inc(&count); + + /* Test 32bit Atomic Exchange */ + nt32.u32 = (uint32_t)rte_rand(); + nt32.u8[3] = get_crc8(&nt32.u8[0], sizeof(nt32) - 1); + ot32.u32 = rte_atomic32_exchange(&token32, nt32.u32); + if (ot32.u8[3] != get_crc8(&ot32.u8[0], sizeof(ot32) - 1)) + rte_atomic64_inc(&count); + + /* Test 16bit Atomic Exchange */ + nt16.u16 = (uint16_t)rte_rand(); + nt16.u8[1] = get_crc8(&nt16.u8[0], sizeof(nt16) - 1); + ot16.u16 = rte_atomic16_exchange(&token16, nt16.u16); + if (ot16.u8[1] != get_crc8(&ot16.u8[0], sizeof(ot16) - 1)) + rte_atomic64_inc(&count); + } + + return 0; +} static int test_atomic(void) { @@ -461,7 +597,38 @@ test_atomic(void) } #endif + /* + * Test 16/32/64bit atomic exchange. + */ + test64_t t; + + printf("exchange test\n"); + + rte_atomic32_clear(&synchro); + rte_atomic64_clear(&count); + + /* Generate the CRC8 lookup table */ + build_crc8_table(); + + /* Create the initial tokens used by the test */ + t.u64 = rte_rand(); + token16 = (get_crc8(&t.u8[0], sizeof(token16) - 1) << 8) + | (t.u16[0] & 0x00ff); + token32 = ((uint32_t)get_crc8(&t.u8[0], sizeof(token32) - 1) << 24) + | (t.u32[0] & 0x00ffffff); + token64 = ((uint64_t)get_crc8(&t.u8[0], sizeof(token64) - 1) << 56) + | (t.u64 & 0x00ffffffffffffff); + + rte_eal_mp_remote_launch(test_atomic_exchange, NULL, SKIP_MASTER); + rte_atomic32_set(&synchro, 1); + rte_eal_mp_wait_lcore(); + rte_atomic32_clear(&synchro); + + if (rte_atomic64_read(&count) > 0) { + printf("Atomic exchange test failed\n"); + return -1; + } + return 0; } - REGISTER_TEST_COMMAND(atomic_autotest, test_atomic); -- 2.20.1