From: Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com
Built-in benchmark fill_buf generates stressful memory bandwidth and cache traffic.
Later it will be used as a default benchmark by various resctrl tests such as MBA (Memory Bandwidth Allocation) and MBM (Memory Bandwidth Monitoring) tests.
Signed-off-by: Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com Co-developed-by: Babu Moger babu.moger@amd.com Signed-off-by: Babu Moger babu.moger@amd.com Co-developed-by: Fenghua Yu fenghua.yu@intel.com Signed-off-by: Fenghua Yu fenghua.yu@intel.com --- tools/testing/selftests/resctrl/fill_buf.c | 207 +++++++++++++++++++++ 1 file changed, 207 insertions(+) create mode 100644 tools/testing/selftests/resctrl/fill_buf.c
diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c new file mode 100644 index 000000000000..b76bf6a4a0a5 --- /dev/null +++ b/tools/testing/selftests/resctrl/fill_buf.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fill_buf benchmark + * + * Copyright (C) 2018 Intel Corporation + * + * Authors: + * Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com, + * Fenghua Yu fenghua.yu@intel.com + */ +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <inttypes.h> +#include <malloc.h> +#include <string.h> + +#include "resctrl.h" + +#define CL_SIZE (64) +#define PAGE_SIZE (4 * 1024) +#define MB (1024 * 1024) + +static unsigned char *startptr; + +static void sb(void) +{ +#if defined(__i386) || defined(__x86_64) + asm volatile("sfence\n\t" + : : : "memory"); +#endif +} + +static void ctrl_handler(int signo) +{ + free(startptr); + printf("\nEnding\n"); + sb(); + exit(EXIT_SUCCESS); +} + +static void cl_flush(void *p) +{ +#if defined(__i386) || defined(__x86_64) + asm volatile("clflush (%0)\n\t" + : : "r"(p) : "memory"); +#endif +} + +static void mem_flush(void *p, size_t s) +{ + char *cp = (char *)p; + size_t i = 0; + + s = s / CL_SIZE; /* mem size in cache llines */ + + for (i = 0; i < s; i++) + cl_flush(&cp[i * CL_SIZE]); + + sb(); +} + +static void *malloc_and_init_memory(size_t s) +{ + uint64_t *p64; + size_t s64; + + void *p = memalign(PAGE_SIZE, s); + + p64 = (uint64_t *)p; + s64 = s / sizeof(uint64_t); + + while (s64 > 0) { + *p64 = (uint64_t)rand(); + p64 += (CL_SIZE / sizeof(uint64_t)); + s64 -= (CL_SIZE / sizeof(uint64_t)); + } + + return p; +} + +static int fill_one_span_read(unsigned char *start_ptr, unsigned char *end_ptr) +{ + unsigned char sum, *p; + + sum = 0; + p = start_ptr; + while (p < end_ptr) { + sum += *p; + p += (CL_SIZE / 2); + } + + return sum; +} + +static +void fill_one_span_write(unsigned char *start_ptr, unsigned char *end_ptr) +{ + unsigned char *p; + + p = start_ptr; + while (p < end_ptr) { + *p = '1'; + p += (CL_SIZE / 2); + } +} + +static int fill_cache_read(unsigned char *start_ptr, unsigned char *end_ptr, + char *resctrl_val) +{ + int ret = 0; + FILE *fp; + + while (1) + ret = fill_one_span_read(start_ptr, end_ptr); + + /* Consume read result so that reading memory is not optimized out. */ + fp = fopen("/dev/null", "w"); + if (!fp) + perror("Unable to write to /dev/null"); + fprintf(fp, "Sum: %d ", ret); + fclose(fp); + + return 0; +} + +static int fill_cache_write(unsigned char *start_ptr, unsigned char *end_ptr, + char *resctrl_val) +{ + while (1) + fill_one_span_write(start_ptr, end_ptr); + + return 0; +} + +static int +fill_cache(unsigned long long buf_size, int malloc_and_init, int memflush, + int op, char *resctrl_val) +{ + unsigned char *start_ptr, *end_ptr; + unsigned long long i; + int ret; + + if (malloc_and_init) + start_ptr = malloc_and_init_memory(buf_size); + else + start_ptr = malloc(buf_size); + + if (!start_ptr) + return -1; + + startptr = start_ptr; + end_ptr = start_ptr + buf_size; + + /* + * It's better to touch the memory once to avoid any compiler + * optimizations + */ + if (!malloc_and_init) { + for (i = 0; i < buf_size; i++) + *start_ptr++ = (unsigned char)rand(); + } + + start_ptr = startptr; + + /* Flush the memory before using to avoid "cache hot pages" effect */ + if (memflush) + mem_flush(start_ptr, buf_size); + + if (op == 0) + ret = fill_cache_read(start_ptr, end_ptr, resctrl_val); + else + ret = fill_cache_write(start_ptr, end_ptr, resctrl_val); + + if (ret) { + printf("\n Errror in fill cache read/write...\n"); + return -1; + } + + free(startptr); + + return 0; +} + +int run_fill_buf(unsigned long span, int malloc_and_init_memory, + int memflush, int op, char *resctrl_val) +{ + unsigned long long cache_size = span; + int ret; + + /* set up ctrl-c handler */ + if (signal(SIGINT, ctrl_handler) == SIG_ERR) + printf("Failed to catch SIGINT!\n"); + if (signal(SIGHUP, ctrl_handler) == SIG_ERR) + printf("Failed to catch SIGHUP!\n"); + + ret = fill_cache(cache_size, malloc_and_init_memory, memflush, op, + resctrl_val); + if (ret) { + printf("\n Errror in fill cache\n"); + return -1; + } + + return 0; +}