diff options
Diffstat (limited to 'src/basic/procfs-util.c')
| -rw-r--r-- | src/basic/procfs-util.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/basic/procfs-util.c b/src/basic/procfs-util.c index 9bb42cc7ba..a159e344b3 100644 --- a/src/basic/procfs-util.c +++ b/src/basic/procfs-util.c @@ -3,6 +3,8 @@ #include <errno.h> #include "alloc-util.h" +#include "def.h" +#include "fd-util.h" #include "fileio.h" #include "parse-util.h" #include "process-util.h" @@ -136,3 +138,130 @@ int procfs_tasks_get_current(uint64_t *ret) { return safe_atou64(nr, ret); } + +static uint64_t calc_gcd64(uint64_t a, uint64_t b) { + + while (b > 0) { + uint64_t t; + + t = a % b; + + a = b; + b = t; + } + + return a; +} + +int procfs_cpu_get_usage(nsec_t *ret) { + _cleanup_free_ char *first_line = NULL; + unsigned long user_ticks, nice_ticks, system_ticks, irq_ticks, softirq_ticks, + guest_ticks = 0, guest_nice_ticks = 0; + long ticks_per_second; + uint64_t sum, gcd, a, b; + const char *p; + int r; + + assert(ret); + + r = read_one_line_file("/proc/stat", &first_line); + if (r < 0) + return r; + + p = first_word(first_line, "cpu"); + if (!p) + return -EINVAL; + + if (sscanf(p, "%lu %lu %lu %*u %*u %lu %lu %*u %lu %lu", + &user_ticks, + &nice_ticks, + &system_ticks, + &irq_ticks, + &softirq_ticks, + &guest_ticks, + &guest_nice_ticks) < 5) /* we only insist on the first five fields */ + return -EINVAL; + + ticks_per_second = sysconf(_SC_CLK_TCK); + if (ticks_per_second < 0) + return -errno; + assert(ticks_per_second > 0); + + sum = (uint64_t) user_ticks + (uint64_t) nice_ticks + (uint64_t) system_ticks + + (uint64_t) irq_ticks + (uint64_t) softirq_ticks + + (uint64_t) guest_ticks + (uint64_t) guest_nice_ticks; + + /* Let's reduce this fraction before we apply it to avoid overflows when converting this to µsec */ + gcd = calc_gcd64(NSEC_PER_SEC, ticks_per_second); + + a = (uint64_t) NSEC_PER_SEC / gcd; + b = (uint64_t) ticks_per_second / gcd; + + *ret = DIV_ROUND_UP((nsec_t) sum * (nsec_t) a, (nsec_t) b); + return 0; +} + +int procfs_memory_get_current(uint64_t *ret) { + uint64_t mem_total = UINT64_MAX, mem_free = UINT64_MAX; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(ret); + + f = fopen("/proc/meminfo", "re"); + if (!f) + return -errno; + + for (;;) { + _cleanup_free_ char *line = NULL; + uint64_t *v; + char *p, *e; + size_t n; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; /* EOF: Couldn't find one or both fields? */ + + p = first_word(line, "MemTotal:"); + if (p) + v = &mem_total; + else { + p = first_word(line, "MemFree:"); + if (p) + v = &mem_free; + else + continue; + } + + /* Determine length of numeric value */ + n = strspn(p, DIGITS); + if (n == 0) + return -EINVAL; + e = p + n; + + /* Ensure the line ends in " kB" */ + n = strspn(e, WHITESPACE); + if (n == 0) + return -EINVAL; + if (!streq(e + n, "kB")) + return -EINVAL; + + *e = 0; + r = safe_atou64(p, v); + if (r < 0) + return r; + if (*v == UINT64_MAX) + return -EINVAL; + + if (mem_total != UINT64_MAX && mem_free != UINT64_MAX) + break; + } + + if (mem_free > mem_total) + return -EINVAL; + + *ret = (mem_total - mem_free) * 1024U; + return 0; +} |