MemoryIdler::defaultIdleTimeout(std::chrono::seconds(5));
-/// Calls mallctl, optionally reading and/or writing an unsigned value
-/// if in and/or out is non-null. Logs on error
-static unsigned mallctlWrapper(const char* cmd, const unsigned* in,
- unsigned* out) {
- size_t outLen = sizeof(unsigned);
+// Calls mallctl, optionally reading a value of type <T> if out is
+// non-null. Logs on error.
+template <typename T>
+static int mallctlRead(const char* cmd, T* out) {
+ size_t outLen = sizeof(T);
int err = mallctl(cmd,
out, out ? &outLen : nullptr,
- const_cast<unsigned*>(in), in ? sizeof(unsigned) : 0);
+ nullptr, 0);
if (err != 0) {
FB_LOG_EVERY_MS(WARNING, 10000)
<< "mallctl " << cmd << ": " << strerror(err) << " (" << err << ")";
return err;
}
+static int mallctlCall(const char* cmd) {
+ // Use <unsigned> rather than <void> to avoid sizeof(void).
+ return mallctlRead<unsigned>(cmd, nullptr);
+}
+
void MemoryIdler::flushLocalMallocCaches() {
if (usingJEMalloc()) {
if (!mallctl || !mallctlnametomib || !mallctlbymib) {
}
// "tcache.flush" was renamed to "thread.tcache.flush" in jemalloc 3
- (void)mallctlWrapper("thread.tcache.flush", nullptr, nullptr);
+ mallctlCall("thread.tcache.flush");
// By default jemalloc has 4 arenas per cpu, and then assigns each
// thread to one of those arenas. This means that in any service
// purging the arenas is counter-productive. We use the heuristic
// that if narenas <= 2 * num_cpus then we shouldn't do anything here,
// which detects when the narenas has been reduced from the default
- unsigned narenas, arenaForCurrent;
+ size_t narenas;
+ unsigned arenaForCurrent;
size_t mib[3];
size_t miblen = 3;
- if (mallctlWrapper("opt.narenas", nullptr, &narenas) == 0 &&
+ if (mallctlRead<size_t>("opt.narenas", &narenas) == 0 &&
narenas > 2 * CacheLocality::system().numCpus &&
- mallctlWrapper("thread.arena", nullptr, &arenaForCurrent) == 0 &&
+ mallctlRead<unsigned>("thread.arena", &arenaForCurrent) == 0 &&
mallctlnametomib("arena.0.purge", mib, &miblen) == 0) {
mib[1] = size_t(arenaForCurrent);
mallctlbymib(mib, miblen, nullptr, nullptr, nullptr, 0);