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-rw-r--r--kernel/tools/testing/selftests/size/get_size.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/size/get_size.c b/kernel/tools/testing/selftests/size/get_size.c
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+++ b/kernel/tools/testing/selftests/size/get_size.c
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+/*
+ * Copyright 2014 Sony Mobile Communications Inc.
+ *
+ * Licensed under the terms of the GNU GPL License version 2
+ *
+ * Selftest for runtime system size
+ *
+ * Prints the amount of RAM that the currently running system is using.
+ *
+ * This program tries to be as small as possible itself, to
+ * avoid perturbing the system memory utilization with its
+ * own execution. It also attempts to have as few dependencies
+ * on kernel features as possible.
+ *
+ * It should be statically linked, with startup libs avoided.
+ * It uses no library calls, and only the following 3 syscalls:
+ * sysinfo(), write(), and _exit()
+ *
+ * For output, it avoids printf (which in some C libraries
+ * has large external dependencies) by implementing it's own
+ * number output and print routines, and using __builtin_strlen()
+ */
+
+#include <sys/sysinfo.h>
+#include <unistd.h>
+
+#define STDOUT_FILENO 1
+
+static int print(const char *s)
+{
+ return write(STDOUT_FILENO, s, __builtin_strlen(s));
+}
+
+static inline char *num_to_str(unsigned long num, char *buf, int len)
+{
+ unsigned int digit;
+
+ /* put digits in buffer from back to front */
+ buf += len - 1;
+ *buf = 0;
+ do {
+ digit = num % 10;
+ *(--buf) = digit + '0';
+ num /= 10;
+ } while (num > 0);
+
+ return buf;
+}
+
+static int print_num(unsigned long num)
+{
+ char num_buf[30];
+
+ return print(num_to_str(num, num_buf, sizeof(num_buf)));
+}
+
+static int print_k_value(const char *s, unsigned long num, unsigned long units)
+{
+ unsigned long long temp;
+ int ccode;
+
+ print(s);
+
+ temp = num;
+ temp = (temp * units)/1024;
+ num = temp;
+ ccode = print_num(num);
+ print("\n");
+ return ccode;
+}
+
+/* this program has no main(), as startup libraries are not used */
+void _start(void)
+{
+ int ccode;
+ struct sysinfo info;
+ unsigned long used;
+
+ print("Testing system size.\n");
+ print("1..1\n");
+
+ ccode = sysinfo(&info);
+ if (ccode < 0) {
+ print("not ok 1 get runtime memory use\n");
+ print("# could not get sysinfo\n");
+ _exit(ccode);
+ }
+ /* ignore cache complexities for now */
+ used = info.totalram - info.freeram - info.bufferram;
+ print_k_value("ok 1 get runtime memory use # size = ", used,
+ info.mem_unit);
+
+ print("# System runtime memory report (units in Kilobytes):\n");
+ print_k_value("# Total: ", info.totalram, info.mem_unit);
+ print_k_value("# Free: ", info.freeram, info.mem_unit);
+ print_k_value("# Buffer: ", info.bufferram, info.mem_unit);
+ print_k_value("# In use: ", used, info.mem_unit);
+
+ _exit(0);
+}