# HG changeset patch
# User tschatzl
# Date 1540989837 -3600
# Node ID 08041b0d7c085b85fe77737320f5b4c81d889532
# Parent 418fb8bb5151248d6d4ebb6abfd27a2dcccef1d9
6490394: G1: Allow heap shrinking / memory unmapping after reclaiming regions during Remark
Reviewed-by: sjohanss, sangheki
diff -r 418fb8bb5151 -r 08041b0d7c08 src/hotspot/share/gc/g1/g1CollectedHeap.cpp
--- a/src/hotspot/share/gc/g1/g1CollectedHeap.cpp Wed Oct 31 13:43:57 2018 +0100
+++ b/src/hotspot/share/gc/g1/g1CollectedHeap.cpp Wed Oct 31 13:43:57 2018 +0100
@@ -1043,7 +1043,7 @@
assert(num_free_regions() == 0, "we should not have added any free regions");
rebuild_region_sets(false /* free_list_only */);
abort_refinement();
- resize_if_necessary_after_full_collection();
+ resize_heap_if_necessary();
// Rebuild the strong code root lists for each region
rebuild_strong_code_roots();
@@ -1149,7 +1149,7 @@
clear_all_soft_refs);
}
-void G1CollectedHeap::resize_if_necessary_after_full_collection() {
+void G1CollectedHeap::resize_heap_if_necessary() {
// Capacity, free and used after the GC counted as full regions to
// include the waste in the following calculations.
const size_t capacity_after_gc = capacity();
@@ -1206,7 +1206,7 @@
// Don't expand unless it's significant
size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
- log_debug(gc, ergo, heap)("Attempt heap expansion (capacity lower than min desired capacity after Full GC). "
+ log_debug(gc, ergo, heap)("Attempt heap expansion (capacity lower than min desired capacity). "
"Capacity: " SIZE_FORMAT "B occupancy: " SIZE_FORMAT "B live: " SIZE_FORMAT "B "
"min_desired_capacity: " SIZE_FORMAT "B (" UINTX_FORMAT " %%)",
capacity_after_gc, used_after_gc, used(), minimum_desired_capacity, MinHeapFreeRatio);
@@ -1218,7 +1218,7 @@
// Capacity too large, compute shrinking size
size_t shrink_bytes = capacity_after_gc - maximum_desired_capacity;
- log_debug(gc, ergo, heap)("Attempt heap shrinking (capacity higher than max desired capacity after Full GC). "
+ log_debug(gc, ergo, heap)("Attempt heap shrinking (capacity higher than max desired capacity). "
"Capacity: " SIZE_FORMAT "B occupancy: " SIZE_FORMAT "B live: " SIZE_FORMAT "B "
"maximum_desired_capacity: " SIZE_FORMAT "B (" UINTX_FORMAT " %%)",
capacity_after_gc, used_after_gc, used(), maximum_desired_capacity, MaxHeapFreeRatio);
@@ -1394,8 +1394,8 @@
void G1CollectedHeap::shrink(size_t shrink_bytes) {
_verifier->verify_region_sets_optional();
- // We should only reach here at the end of a Full GC which means we
- // should not not be holding to any GC alloc regions. The method
+ // We should only reach here at the end of a Full GC or during Remark which
+ // means we should not not be holding to any GC alloc regions. The method
// below will make sure of that and do any remaining clean up.
_allocator->abandon_gc_alloc_regions();
@@ -4399,13 +4399,13 @@
}
bool do_heap_region(HeapRegion* r) {
- // After full GC, no region should have a remembered set.
- r->rem_set()->clear(true);
if (r->is_empty()) {
+ assert(r->rem_set()->is_empty(), "Empty regions should have empty remembered sets.");
// Add free regions to the free list
r->set_free();
_hrm->insert_into_free_list(r);
} else if (!_free_list_only) {
+ assert(r->rem_set()->is_empty(), "At this point remembered sets must have been cleared.");
if (r->is_archive() || r->is_humongous()) {
// We ignore archive and humongous regions. We left these sets unchanged.
@@ -4443,10 +4443,9 @@
_archive_allocator->clear_used();
}
}
- assert(used_unlocked() == recalculate_used(),
- "inconsistent used_unlocked(), "
- "value: " SIZE_FORMAT " recalculated: " SIZE_FORMAT,
- used_unlocked(), recalculate_used());
+ assert(used() == recalculate_used(),
+ "inconsistent used(), value: " SIZE_FORMAT " recalculated: " SIZE_FORMAT,
+ used(), recalculate_used());
}
bool G1CollectedHeap::is_in_closed_subset(const void* p) const {
diff -r 418fb8bb5151 -r 08041b0d7c08 src/hotspot/share/gc/g1/g1CollectedHeap.hpp
--- a/src/hotspot/share/gc/g1/g1CollectedHeap.hpp Wed Oct 31 13:43:57 2018 +0100
+++ b/src/hotspot/share/gc/g1/g1CollectedHeap.hpp Wed Oct 31 13:43:57 2018 +0100
@@ -468,9 +468,6 @@
// Callback from VM_G1CollectFull operation, or collect_as_vm_thread.
virtual void do_full_collection(bool clear_all_soft_refs);
- // Resize the heap if necessary after a full collection.
- void resize_if_necessary_after_full_collection();
-
// Callback from VM_G1CollectForAllocation operation.
// This function does everything necessary/possible to satisfy a
// failed allocation request (including collection, expansion, etc.)
@@ -528,6 +525,8 @@
return _g1mm;
}
+ void resize_heap_if_necessary();
+
// Expand the garbage-first heap by at least the given size (in bytes!).
// Returns true if the heap was expanded by the requested amount;
// false otherwise.
diff -r 418fb8bb5151 -r 08041b0d7c08 src/hotspot/share/gc/g1/g1ConcurrentMark.cpp
--- a/src/hotspot/share/gc/g1/g1ConcurrentMark.cpp Wed Oct 31 13:43:57 2018 +0100
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMark.cpp Wed Oct 31 13:43:57 2018 +0100
@@ -1178,6 +1178,8 @@
ClassLoaderDataGraph::purge();
}
+ _g1h->resize_heap_if_necessary();
+
compute_new_sizes();
verify_during_pause(G1HeapVerifier::G1VerifyRemark, VerifyOption_G1UsePrevMarking, "Remark after");
diff -r 418fb8bb5151 -r 08041b0d7c08 test/hotspot/jtreg/gc/g1/humongousObjects/objectGraphTest/TestObjectGraphAfterGC.java
--- a/test/hotspot/jtreg/gc/g1/humongousObjects/objectGraphTest/TestObjectGraphAfterGC.java Wed Oct 31 13:43:57 2018 +0100
+++ b/test/hotspot/jtreg/gc/g1/humongousObjects/objectGraphTest/TestObjectGraphAfterGC.java Wed Oct 31 13:43:57 2018 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -56,29 +56,29 @@
* @run driver ClassFileInstaller sun.hotspot.WhiteBox
* sun.hotspot.WhiteBox$WhiteBoxPermission
*
- * @run main/othervm -Xms200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ * @run main/othervm -Xms200M -Xmx200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:+UnlockExperimentalVMOptions -XX:MaxGCPauseMillis=30000 -XX:G1MixedGCLiveThresholdPercent=100 -XX:G1HeapWastePercent=0
* -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectGraphAfterGC_MIXED_GC.gc.log -XX:MaxTenuringThreshold=1
* -XX:G1MixedGCCountTarget=1 -XX:G1OldCSetRegionThresholdPercent=100 -XX:SurvivorRatio=1 -XX:InitiatingHeapOccupancyPercent=0
* gc.g1.humongousObjects.objectGraphTest.TestObjectGraphAfterGC MIXED_GC
*
- * @run main/othervm -Xms200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ * @run main/othervm -Xms200M -Xmx200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xlog:gc*=debug:file=TestObjectGraphAfterGC_YOUNG_GC.gc.log
* gc.g1.humongousObjects.objectGraphTest.TestObjectGraphAfterGC YOUNG_GC
*
- * @run main/othervm -Xms200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ * @run main/othervm -Xms200M -Xmx200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectGraphAfterGC_FULL_GC.gc.log
* gc.g1.humongousObjects.objectGraphTest.TestObjectGraphAfterGC FULL_GC
*
- * @run main/othervm -Xms200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ * @run main/othervm -Xms200M -Xmx200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectGraphAfterGC_FULL_GC_MEMORY_PRESSURE.gc.log
* gc.g1.humongousObjects.objectGraphTest.TestObjectGraphAfterGC FULL_GC_MEMORY_PRESSURE
*
- * @run main/othervm -Xms200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ * @run main/othervm -Xms200M -Xmx200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectGraphAfterGC_CMC.gc.log -XX:MaxTenuringThreshold=16
* gc.g1.humongousObjects.objectGraphTest.TestObjectGraphAfterGC CMC
*
- * @run main/othervm -Xms200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ * @run main/othervm -Xms200M -Xmx200M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectGraphAfterGC_CMC_NO_SURV_ROOTS.gc.log -XX:MaxTenuringThreshold=1
* gc.g1.humongousObjects.objectGraphTest.TestObjectGraphAfterGC CMC_NO_SURV_ROOTS
*