diff --git a/src/hotspot/share/gc/shenandoah/heuristics/shenandoahOldHeuristics.cpp b/src/hotspot/share/gc/shenandoah/heuristics/shenandoahOldHeuristics.cpp
index 7fb048f876e..e54d3a9b6e3 100644
--- a/src/hotspot/share/gc/shenandoah/heuristics/shenandoahOldHeuristics.cpp
+++ b/src/hotspot/share/gc/shenandoah/heuristics/shenandoahOldHeuristics.cpp
@@ -192,7 +192,11 @@ bool ShenandoahOldHeuristics::prime_collection_set(ShenandoahCollectionSet* coll
// We have added the last of our collection candidates to a mixed collection.
// Any triggers that occurred during mixed evacuations may no longer be valid. They can retrigger if appropriate.
clear_triggers();
- _old_generation->transition_to(ShenandoahOldGeneration::IDLE);
+ if (has_coalesce_and_fill_candidates()) {
+ _old_generation->transition_to(ShenandoahOldGeneration::WAITING_FOR_FILL);
+ } else {
+ _old_generation->transition_to(ShenandoahOldGeneration::IDLE);
+ }
} else if (included_old_regions == 0) {
// We have candidates, but none were included for evacuation - are they all pinned?
// or did we just not have enough room for any of them in this collection set?
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahControlThread.cpp b/src/hotspot/share/gc/shenandoah/shenandoahControlThread.cpp
index 174a81d1dd1..263d520fea0 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahControlThread.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahControlThread.cpp
@@ -852,8 +852,9 @@ bool ShenandoahControlThread::is_explicit_gc(GCCause::Cause cause) const {
}
bool ShenandoahControlThread::is_implicit_gc(GCCause::Cause cause) const {
- return !is_explicit_gc(cause) &&
- (cause != GCCause::_shenandoah_concurrent_gc);
+ return !is_explicit_gc(cause)
+ && cause != GCCause::_shenandoah_concurrent_gc
+ && cause != GCCause::_no_gc;
}
void ShenandoahControlThread::request_gc(GCCause::Cause cause) {
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp b/src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp
index 4438a1725ce..ecf4f2ab1b3 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp
@@ -1302,7 +1302,7 @@ void ShenandoahFreeSet::log_status() {
#ifdef ASSERT
// Dump of the FreeSet details is only enabled if assertions are enabled
- {
+ if (LogTarget(Debug, gc, free)::is_enabled()) {
#define BUFFER_SIZE 80
size_t retired_old = 0;
size_t retired_old_humongous = 0;
@@ -1324,10 +1324,10 @@ void ShenandoahFreeSet::log_status() {
for (uint i = 0; i < BUFFER_SIZE; i++) {
buffer[i] = '\0';
}
- log_info(gc, free)("FreeSet map legend:"
+ log_debug(gc, free)("FreeSet map legend:"
" M:mutator_free C:collector_free O:old_collector_free"
" H:humongous ~:retired old _:retired young");
- log_info(gc, free)(" mutator free range [" SIZE_FORMAT ".." SIZE_FORMAT "], "
+ log_debug(gc, free)(" mutator free range [" SIZE_FORMAT ".." SIZE_FORMAT "], "
" collector free range [" SIZE_FORMAT ".." SIZE_FORMAT "], "
"old collector free range [" SIZE_FORMAT ".." SIZE_FORMAT "] allocates from %s",
_free_sets.leftmost(Mutator), _free_sets.rightmost(Mutator),
@@ -1339,7 +1339,7 @@ void ShenandoahFreeSet::log_status() {
ShenandoahHeapRegion *r = _heap->get_region(i);
uint idx = i % 64;
if ((i != 0) && (idx == 0)) {
- log_info(gc, free)(" %6u: %s", i-64, buffer);
+ log_debug(gc, free)(" %6u: %s", i-64, buffer);
}
if (_free_sets.in_free_set(i, Mutator)) {
assert(!r->is_old(), "Old regions should not be in mutator_free set");
@@ -1384,7 +1384,7 @@ void ShenandoahFreeSet::log_status() {
} else {
remnant = 64;
}
- log_info(gc, free)(" %6u: %s", (uint) (_heap->num_regions() - remnant), buffer);
+ log_debug(gc, free)(" %6u: %s", (uint) (_heap->num_regions() - remnant), buffer);
size_t total_young = retired_young + retired_young_humongous;
size_t total_old = retired_old + retired_old_humongous;
}
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahGlobalGeneration.cpp b/src/hotspot/share/gc/shenandoah/shenandoahGlobalGeneration.cpp
index 982d3525f80..59163d1f29c 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahGlobalGeneration.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahGlobalGeneration.cpp
@@ -74,7 +74,7 @@ void ShenandoahGlobalGeneration::set_concurrent_mark_in_progress(bool in_progres
// because the global generation includes the old generation, but we
// want the global collect to start from a clean slate and we don't want
// any stale state in the old generation.
- heap->cancel_old_gc();
+ assert(!heap->is_concurrent_old_mark_in_progress(), "Old cycle should not be running.");
}
heap->set_concurrent_young_mark_in_progress(in_progress);
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
index 55420e2625e..a3c9dce3ee9 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
@@ -1163,18 +1163,24 @@ void ShenandoahHeap::retire_plab(PLAB* plab) {
void ShenandoahHeap::cancel_old_gc() {
shenandoah_assert_safepoint();
assert(_old_generation != nullptr, "Should only have mixed collections in generation mode.");
- log_info(gc)("Terminating old gc cycle.");
-
- // Stop marking
- old_generation()->cancel_marking();
- // Stop coalescing undead objects
- set_prepare_for_old_mark_in_progress(false);
- // Stop tracking old regions
- old_heuristics()->abandon_collection_candidates();
- // Remove old generation access to young generation mark queues
- young_generation()->set_old_gen_task_queues(nullptr);
- // Transition to IDLE now.
- _old_generation->transition_to(ShenandoahOldGeneration::IDLE);
+ if (_old_generation->state() == ShenandoahOldGeneration::IDLE) {
+ assert(!old_generation()->is_concurrent_mark_in_progress(), "Cannot be marking in IDLE");
+ assert(!old_heuristics()->has_coalesce_and_fill_candidates(), "Cannot have coalesce and fill candidates in IDLE");
+ assert(!old_heuristics()->unprocessed_old_collection_candidates(), "Cannot have mixed collection candidates in IDLE");
+ assert(!young_generation()->is_bootstrap_cycle(), "Cannot have old mark queues if IDLE");
+ } else {
+ log_info(gc)("Terminating old gc cycle.");
+ // Stop marking
+ old_generation()->cancel_marking();
+ // Stop coalescing undead objects
+ set_prepare_for_old_mark_in_progress(false);
+ // Stop tracking old regions
+ old_heuristics()->abandon_collection_candidates();
+ // Remove old generation access to young generation mark queues
+ young_generation()->set_old_gen_task_queues(nullptr);
+ // Transition to IDLE now.
+ _old_generation->transition_to(ShenandoahOldGeneration::IDLE);
+ }
}
// xfer_limit is the maximum we're able to transfer from young to old
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahRegulatorThread.cpp b/src/hotspot/share/gc/shenandoah/shenandoahRegulatorThread.cpp
index e082cdcde12..8e4ec64e0a5 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahRegulatorThread.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahRegulatorThread.cpp
@@ -76,10 +76,12 @@ void ShenandoahRegulatorThread::regulate_concurrent_cycles() {
log_info(gc)("Heuristics request for global (unload classes) accepted.");
}
} else {
- if (start_old_cycle()) {
- log_info(gc)("Heuristics request for old collection accepted");
- } else if (start_young_cycle()) {
- log_info(gc)("Heuristics request for young collection accepted");
+ if (_young_heuristics->should_start_gc()) {
+ if (start_old_cycle()) {
+ log_info(gc)("Heuristics request for old collection accepted");
+ } else if (request_concurrent_gc(YOUNG)) {
+ log_info(gc)("Heuristics request for young collection accepted");
+ }
}
}
} else if (mode == ShenandoahControlThread::servicing_old) {