/* * Copyright (c) 2019 Arm Limited. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include <vppinfra/mem.h> #include <vppinfra/cache.h> #include <vppinfra/lock.h> #include <pthread.h> #include <vppinfra/format.h> #include <vppinfra/error.h> #include <vppinfra/time.h> #include <sched.h> #include <stdlib.h> #include <vppinfra/atomics.h> static u32 all_threads_online = 0; typedef struct { uword threads_per_core; uword cpu_mask; uword num_cores; uword increment_per_thread; clib_spinlock_t slock; uword shared_count; uword iterations; } spinlock_test_main_t; void * inc_shared_counter (void *arg) { f64 *time = vec_new (f64, 1); *time = 0; spinlock_test_main_t *stm = arg; /* Wait for all threads to be created */ while (!clib_atomic_load_acq_n (&all_threads_online)); f64 start = clib_cpu_time_now (); for (uword i = 0; i < stm->increment_per_thread; i++) { clib_spinlock_lock (&stm->slock); stm->shared_count++; clib_spinlock_unlock (&stm->slock); } *time = clib_cpu_time_now () - start; return time; } unsigned test_spinlock (spinlock_test_main_t * stm, f64 * elapse_time) { int error; uword num_threads = stm->num_cores * stm->threads_per_core; pthread_t pthread[num_threads]; cpu_set_t cpuset; unsigned cores_set = 0, cpu_id = 0; for (unsigned cpu_mask = stm->cpu_mask; cpu_mask; cpu_mask >>= 1) { if (!(cpu_mask & 1)) { cpu_id++; continue; } CPU_ZERO (&cpuset); CPU_SET (cpu_id, &cpuset); for (uword t_num = 0; t_num < stm->threads_per_core; t_num++) { uword t_index = cores_set * stm->threads_per_core + t_num; if ((error = pthread_create (&pthread[t_index], NULL, &inc_shared_counter, stm))) clib_unix_warning ("pthread_create failed with %d", error); if ((error = pthread_setaffinity_np (pthread[t_index], sizeof (cpu_set_t), &cpuset))) clib_unix_warning ("pthread_setaffinity_np failed with %d", error); } cores_set++; cpu_id++; } /* Launch all threads */ clib_atomic_store_rel_n (&all_threads_online, 1); for (uword thread_num = 0; thread_num < num_threads; thread_num++) { f64 *time; if ((error = pthread_join (pthread[thread_num], (void *) &time))) clib_unix_warning ("pthread_join failed with %d", error); *elapse_time += *time; vec_free (time); } fformat (stdout, "Time elapsed: %.4e cycles\n", *elapse_time); return stm->shared_count; } uword num_cores_in_cpu_mask (uword mask) { uword num_cores = 0; for (uword cpu_mask = mask; cpu_mask; cpu_mask >>= 1) num_cores += (cpu_mask & 1); return num_cores; } int test_spinlock_main (unformat_input_t * i) { spinlock_test_main_t _stm, *stm = &_stm; clib_memset (stm, 0, sizeof (spinlock_test_main_t)); while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT) { if (0 == unformat (i, "threads/core %d", &stm->threads_per_core) && 0 == unformat (i, "cpu_mask %x", &stm->cpu_mask) && 0 == unformat (i, "increment %d", &stm->increment_per_thread) && 0 == unformat (i, "iterations %d", &stm->iterations)) { clib_unix_warning ("unknown input '%U'", format_unformat_error, i); return 1; } } stm->num_cores = num_cores_in_cpu_mask (stm->cpu_mask); uword total_increment = stm->threads_per_core * stm->num_cores * stm->increment_per_thread; clib_spinlock_init (&stm->slock); f64 average_time = 0; for (uword trial = 0; trial < stm->iterations; trial++) { stm->shared_count = 0; f64 elapse_time = 0; if (test_spinlock (stm, &elapse_time) != total_increment) { clib_spinlock_free (&stm->slock); fformat (stdout, "FAILED: expected count: %d, actual count: %d\n", total_increment, stm->shared_count); return 1; } fformat (stdout, "Trial %d SUCCESS: %d = %d\n", trial, stm->shared_count, total_increment); average_time = (average_time * trial + elapse_time) / (trial + 1); fformat (stdout, "Average lock/unlock cycles %.4e\n", average_time); } clib_spinlock_free (&stm->slock); return 0; } #ifdef CLIB_UNIX /** Launches a number of threads to simultaneously increment a global counter, and records timestamps for spinlock performance benchmarking @param "threads/core [# threads/core]" - number of threads per core @param "cpu_mask [cpu_mask]" - cpu hex string e.g. input ff sets cpus 0 - 7 @param "increment [# increments]" - number of increments per threads @param "iterations [# iterations]" - number of iterations @returns exit code */ int main (int argc, char *argv[]) { unformat_input_t i; i32 ret; clib_time_t time; clib_mem_init (0, 3ULL << 30); clib_time_init (&time); unformat_init_command_line (&i, argv); ret = test_spinlock_main (&i); unformat_free (&i); return ret; } #endif /* CLIB_UNIX */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */