--- a/src/hotspot/os/linux/os_linux.cpp Mon Apr 08 21:39:43 2019 +0000
+++ b/src/hotspot/os/linux/os_linux.cpp Mon Apr 08 14:36:33 2019 +0200
@@ -227,6 +227,82 @@
return phys_mem;
}
+static uint64_t initial_total_ticks = 0;
+static uint64_t initial_steal_ticks = 0;
+static bool has_initial_tick_info = false;
+
+static void next_line(FILE *f) {
+ int c;
+ do {
+ c = fgetc(f);
+ } while (c != '\n' && c != EOF);
+}
+
+bool os::Linux::get_tick_information(CPUPerfTicks* pticks, int which_logical_cpu) {
+ FILE* fh;
+ uint64_t userTicks, niceTicks, systemTicks, idleTicks;
+ // since at least kernel 2.6 : iowait: time waiting for I/O to complete
+ // irq: time servicing interrupts; softirq: time servicing softirqs
+ uint64_t iowTicks = 0, irqTicks = 0, sirqTicks= 0;
+ // steal (since kernel 2.6.11): time spent in other OS when running in a virtualized environment
+ uint64_t stealTicks = 0;
+ // guest (since kernel 2.6.24): time spent running a virtual CPU for guest OS under the
+ // control of the Linux kernel
+ uint64_t guestNiceTicks = 0;
+ int logical_cpu = -1;
+ const int required_tickinfo_count = (which_logical_cpu == -1) ? 4 : 5;
+ int n;
+
+ memset(pticks, 0, sizeof(CPUPerfTicks));
+
+ if ((fh = fopen("/proc/stat", "r")) == NULL) {
+ return false;
+ }
+
+ if (which_logical_cpu == -1) {
+ n = fscanf(fh, "cpu " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
+ UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
+ UINT64_FORMAT " " UINT64_FORMAT " ",
+ &userTicks, &niceTicks, &systemTicks, &idleTicks,
+ &iowTicks, &irqTicks, &sirqTicks,
+ &stealTicks, &guestNiceTicks);
+ } else {
+ // Move to next line
+ next_line(fh);
+
+ // find the line for requested cpu faster to just iterate linefeeds?
+ for (int i = 0; i < which_logical_cpu; i++) {
+ next_line(fh);
+ }
+
+ n = fscanf(fh, "cpu%u " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
+ UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
+ UINT64_FORMAT " " UINT64_FORMAT " ",
+ &logical_cpu, &userTicks, &niceTicks,
+ &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks,
+ &stealTicks, &guestNiceTicks);
+ }
+
+ fclose(fh);
+ if (n < required_tickinfo_count || logical_cpu != which_logical_cpu) {
+ return false;
+ }
+ pticks->used = userTicks + niceTicks;
+ pticks->usedKernel = systemTicks + irqTicks + sirqTicks;
+ pticks->total = userTicks + niceTicks + systemTicks + idleTicks +
+ iowTicks + irqTicks + sirqTicks + stealTicks + guestNiceTicks;
+
+ if (n > required_tickinfo_count + 3) {
+ pticks->steal = stealTicks;
+ pticks->has_steal_ticks = true;
+ } else {
+ pticks->steal = 0;
+ pticks->has_steal_ticks = false;
+ }
+
+ return true;
+}
+
// Return true if user is running as root.
bool os::have_special_privileges() {
@@ -1977,6 +2053,8 @@
os::Linux::print_container_info(st);
os::Linux::print_virtualization_info(st);
+
+ os::Linux::print_steal_info(st);
}
// Try to identify popular distros.
@@ -2265,6 +2343,24 @@
#endif
}
+void os::Linux::print_steal_info(outputStream* st) {
+ if (has_initial_tick_info) {
+ CPUPerfTicks pticks;
+ bool res = os::Linux::get_tick_information(&pticks, -1);
+
+ if (res && pticks.has_steal_ticks) {
+ uint64_t steal_ticks_difference = pticks.steal - initial_steal_ticks;
+ uint64_t total_ticks_difference = pticks.total - initial_total_ticks;
+ double steal_ticks_perc = 0.0;
+ if (total_ticks_difference != 0) {
+ steal_ticks_perc = (double) steal_ticks_difference / total_ticks_difference;
+ }
+ st->print_cr("Steal ticks since vm start: " UINT64_FORMAT, steal_ticks_difference);
+ st->print_cr("Steal ticks percentage since vm start:%7.3f", steal_ticks_perc);
+ }
+ }
+}
+
void os::print_memory_info(outputStream* st) {
st->print("Memory:");
@@ -4989,6 +5085,15 @@
Linux::initialize_os_info();
+ os::Linux::CPUPerfTicks pticks;
+ bool res = os::Linux::get_tick_information(&pticks, -1);
+
+ if (res && pticks.has_steal_ticks) {
+ has_initial_tick_info = true;
+ initial_total_ticks = pticks.total;
+ initial_steal_ticks = pticks.steal;
+ }
+
// _main_thread points to the thread that created/loaded the JVM.
Linux::_main_thread = pthread_self();