diff options
Diffstat (limited to 'kernel/tools/testing/selftests/size/get_size.c')
-rw-r--r-- | kernel/tools/testing/selftests/size/get_size.c | 100 |
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 new file mode 100644 index 000000000..2d1af7cca --- /dev/null +++ b/kernel/tools/testing/selftests/size/get_size.c @@ -0,0 +1,100 @@ +/* + * 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); +} |