From: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>
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@xxxxxxxxx>
Co-developed-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Co-developed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
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@xxxxxxxxx>,
+ * Fenghua Yu <fenghua.yu@xxxxxxxxx>
+ */
+#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;
+}
--
2.19.1
