/*
* Check available memory, only warn/reboot if no swap (left). On an
* embedded system there may not be a swap, so memory leaks can be quite
* nasty. On a "regular" system you do not want to run out of swap.
*/
static void cb(uev_t *w, void *UNUSED(arg), int UNUSED(events))
{
char buf[80];
FILE *fp;
meminfo_t meminfo[] = {
{ "MemTotal:", 0 },
{ "MemFree:", 0 },
{ "Cached:", 0 },
{ "SwapCached:", 0 },
{ "SwapTotal:", 0 },
{ "SwapFree:", 0 },
{ NULL, 0 }
};
fp = fopen(PROC_FILE, "r");
if (!fp) {
DEBUG("Cannot read %s, maybe /proc is not mounted yet", PROC_FILE);
return;
}
/*
* $ cat /proc/meminfo
* MemTotal: 8120568 kB
* MemFree: 2298932 kB
* Cached: 1907240 kB
* SwapCached: 0 kB
* SwapTotal: 15859708 kB
* SwapFree: 15859708 kB
*/
while (fgets(buf, sizeof(buf), fp)) {
int i;
for (i = 0; meminfo[i].str; i++) {
size_t len = strlen(meminfo[i].str);
if (!strncmp(buf, meminfo[i].str, len)) {
char *ptr = buf + len + 1;
while (isspace(*ptr))
ptr++;
sscanf(ptr, "%u kB", &meminfo[i].val);
}
}
}
fclose(fp);
DEBUG("Total RAM: %u kB, free: %u kB, cached: %u kB, Total Swap: %u kB, free: %u kB, cached: %u kB",
meminfo[MEMTOTAL].val, meminfo[MEMFREE].val, meminfo[MEMCACHED].val,
meminfo[SWAPTOTAL].val, meminfo[SWAPFREE].val, meminfo[SWAPCACHED].val);
/* Enable trigger warnings by default only on systems without swap */
if (meminfo[SWAPTOTAL].val == 0) {
double level;
uint32_t free = meminfo[MEMFREE].val + meminfo[MEMCACHED].val;
uint32_t used = meminfo[MEMTOTAL].val - free;
level = (double)used / (double)meminfo[MEMTOTAL].val;
DEBUG("RAM usage level %.0f%%, warning: %.0f%%, critical: %.0f%%",
level * 100, warning * 100, critical * 100);
if (level > warning) {
if (level > critical) {
ERROR("Memory usage too high, %.2f > %0.2f, rebooting system ...", level, critical);
wdt_forced_reboot(w->ctx, getpid(), wdt_plugin_label("meminfo"), WDOG_MEMORY_LEAK);
return;
}
WARN("Memory use very high, %.2f > %0.2f, possible leak!", level, warning);
}
}
}
void reboot_cb(uev_t *w, void *UNUSED(arg), int UNUSED(events))
{
wdt_forced_reboot(w->ctx, 1, "init", WDOG_FORCED_RESET);
}
