--- a/src/hotspot/share/runtime/synchronizer.cpp Tue Nov 27 17:53:17 2018 -0500
+++ b/src/hotspot/share/runtime/synchronizer.cpp Tue Nov 27 18:35:16 2018 -0500
@@ -45,6 +45,7 @@
#include "runtime/stubRoutines.hpp"
#include "runtime/synchronizer.hpp"
#include "runtime/thread.inline.hpp"
+#include "runtime/timer.hpp"
#include "runtime/vframe.hpp"
#include "runtime/vmThread.hpp"
#include "utilities/align.hpp"
@@ -1618,9 +1619,10 @@
}
void ObjectSynchronizer::prepare_deflate_idle_monitors(DeflateMonitorCounters* counters) {
- counters->nInuse = 0; // currently associated with objects
- counters->nInCirculation = 0; // extant
- counters->nScavenged = 0; // reclaimed
+ counters->nInuse = 0; // currently associated with objects
+ counters->nInCirculation = 0; // extant
+ counters->nScavenged = 0; // reclaimed
+ counters->perThreadTimes = 0.0; // per-thread scavenge times
}
void ObjectSynchronizer::deflate_idle_monitors(DeflateMonitorCounters* counters) {
@@ -1660,6 +1662,14 @@
}
void ObjectSynchronizer::finish_deflate_idle_monitors(DeflateMonitorCounters* counters) {
+ if (log_is_enabled(Info, safepoint, cleanup)) {
+ // Report the cumulative time for deflating each thread's idle
+ // monitors. Note: if the work is split among more than one
+ // worker thread, then the reported time will likely be more
+ // than a beginning to end measurement of the phase.
+ log_info(safepoint, cleanup)("deflating per-thread idle monitors, %3.7f secs", counters->perThreadTimes);
+ }
+
gMonitorFreeCount += counters->nScavenged;
// Consider: audit gFreeList to ensure that gMonitorFreeCount and list agree.
@@ -1680,9 +1690,16 @@
ObjectMonitor * freeHeadp = NULL; // Local SLL of scavenged monitors
ObjectMonitor * freeTailp = NULL;
+ elapsedTimer timer;
+
+ if (log_is_enabled(Info, safepoint, cleanup)) {
+ timer.start();
+ }
int deflated_count = deflate_monitor_list(thread->omInUseList_addr(), &freeHeadp, &freeTailp);
+ timer.stop();
+
Thread::muxAcquire(&gListLock, "scavenge - return");
// Adjust counters
@@ -1690,6 +1707,8 @@
thread->omInUseCount -= deflated_count;
counters->nScavenged += deflated_count;
counters->nInuse += thread->omInUseCount;
+ // For now, we only care about cumulative per-thread deflation time.
+ counters->perThreadTimes += timer.seconds();
// Move the scavenged monitors back to the global free list.
if (freeHeadp != NULL) {