selftests/resctrl: Refactor fill_buf functions

There are unnecessary nested calls in fill_buf.c:
  - run_fill_buf() calls fill_cache()
  - alloc_buffer() calls malloc_and_init_memory()

Simplify the code flow and remove those unnecessary call levels by
moving the called code inside the calling function and remove the
duplicated error print.

Resolve the difference in run_fill_buf() and fill_cache() parameter
name into 'buf_size' which is more descriptive than 'span'. Also, while
moving the allocation related code, rename 'p' into 'buf' to be
consistent in naming the variables.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/resctrl/fill_buf.c

@@ -51,29 +51,6 @@ static void mem_flush(unsigned char *buf, size_t buf_size)
 	sb();
 }
 
-static void *malloc_and_init_memory(size_t buf_size)
-{
-	void *p = NULL;
-	uint64_t *p64;
-	size_t s64;
-	int ret;
-
-	ret = posix_memalign(&p, PAGE_SIZE, buf_size);
-	if (ret < 0)
-		return NULL;
-
-	p64 = (uint64_t *)p;
-	s64 = buf_size / 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 *buf, size_t buf_size)
 {
 	unsigned char *end_ptr = buf + buf_size;
@@ -137,12 +114,25 @@ static int fill_cache_write(unsigned char *buf, size_t buf_size, bool once)
 
 static unsigned char *alloc_buffer(size_t buf_size, int memflush)
 {
-	unsigned char *buf;
+	void *buf = NULL;
+	uint64_t *p64;
+	size_t s64;
+	int ret;
 
-	buf = malloc_and_init_memory(buf_size);
-	if (!buf)
+	ret = posix_memalign(&buf, PAGE_SIZE, buf_size);
+	if (ret < 0)
 		return NULL;
 
+	/* Initialize the buffer */
+	p64 = buf;
+	s64 = buf_size / sizeof(uint64_t);
+
+	while (s64 > 0) {
+		*p64 = (uint64_t)rand();
+		p64 += (CL_SIZE / sizeof(uint64_t));
+		s64 -= (CL_SIZE / sizeof(uint64_t));
+	}
+
 	/* Flush the memory before using to avoid "cache hot pages" effect */
 	if (memflush)
 		mem_flush(buf, buf_size);
@@ -150,7 +140,7 @@ static unsigned char *alloc_buffer(size_t buf_size, int memflush)
 	return buf;
 }
 
-static int fill_cache(size_t buf_size, int memflush, int op, bool once)
+int run_fill_buf(size_t buf_size, int memflush, int op, bool once)
 {
 	unsigned char *buf;
 	int ret;
@@ -164,21 +154,6 @@ static int fill_cache(size_t buf_size, int memflush, int op, bool once)
 	else
 		ret = fill_cache_write(buf, buf_size, once);
 	free(buf);
-
-	if (ret) {
-		printf("\n Error in fill cache read/write...\n");
-		return -1;
-	}
-
-	return ret;
-}
-
-int run_fill_buf(size_t span, int memflush, int op, bool once)
-{
-	size_t cache_size = span;
-	int ret;
-
-	ret = fill_cache(cache_size, memflush, op, once);
 	if (ret) {
 		printf("\n Error in fill cache\n");
 		return -1;

tools/testing/selftests/resctrl/resctrl.h

@@ -91,7 +91,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
 			    char *resctrl_val);
 int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
 		    int group_fd, unsigned long flags);
-int run_fill_buf(size_t span, int memflush, int op, bool once);
+int run_fill_buf(size_t buf_size, int memflush, int op, bool once);
 int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *param);
 int mbm_bw_change(int cpu_no, const char * const *benchmark_cmd);
 void tests_cleanup(void);