7144296: PS: Optimize nmethods processing
Summary: Prunes scavenge roots in code list every young GC, promote objects directly pointed by the code immediately
Reviewed-by: johnc, jcoomes
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.cpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.cpp Fri Feb 10 17:40:20 2012 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2012, 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
@@ -247,167 +247,6 @@
}
}
-//
-// This method is pretty bulky. It would be nice to split it up
-// into smaller submethods, but we need to be careful not to hurt
-// performance.
-//
-
-oop PSPromotionManager::copy_to_survivor_space(oop o) {
- assert(PSScavenge::should_scavenge(&o), "Sanity");
-
- oop new_obj = NULL;
-
- // NOTE! We must be very careful with any methods that access the mark
- // in o. There may be multiple threads racing on it, and it may be forwarded
- // at any time. Do not use oop methods for accessing the mark!
- markOop test_mark = o->mark();
-
- // The same test as "o->is_forwarded()"
- if (!test_mark->is_marked()) {
- bool new_obj_is_tenured = false;
- size_t new_obj_size = o->size();
-
- // Find the objects age, MT safe.
- int age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
- test_mark->displaced_mark_helper()->age() : test_mark->age();
-
- // Try allocating obj in to-space (unless too old)
- if (age < PSScavenge::tenuring_threshold()) {
- new_obj = (oop) _young_lab.allocate(new_obj_size);
- if (new_obj == NULL && !_young_gen_is_full) {
- // Do we allocate directly, or flush and refill?
- if (new_obj_size > (YoungPLABSize / 2)) {
- // Allocate this object directly
- new_obj = (oop)young_space()->cas_allocate(new_obj_size);
- } else {
- // Flush and fill
- _young_lab.flush();
-
- HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
- if (lab_base != NULL) {
- _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
- // Try the young lab allocation again.
- new_obj = (oop) _young_lab.allocate(new_obj_size);
- } else {
- _young_gen_is_full = true;
- }
- }
- }
- }
-
- // Otherwise try allocating obj tenured
- if (new_obj == NULL) {
-#ifndef PRODUCT
- if (Universe::heap()->promotion_should_fail()) {
- return oop_promotion_failed(o, test_mark);
- }
-#endif // #ifndef PRODUCT
-
- new_obj = (oop) _old_lab.allocate(new_obj_size);
- new_obj_is_tenured = true;
-
- if (new_obj == NULL) {
- if (!_old_gen_is_full) {
- // Do we allocate directly, or flush and refill?
- if (new_obj_size > (OldPLABSize / 2)) {
- // Allocate this object directly
- new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
- } else {
- // Flush and fill
- _old_lab.flush();
-
- HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
- if(lab_base != NULL) {
- _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
- // Try the old lab allocation again.
- new_obj = (oop) _old_lab.allocate(new_obj_size);
- }
- }
- }
-
- // This is the promotion failed test, and code handling.
- // The code belongs here for two reasons. It is slightly
- // different thatn the code below, and cannot share the
- // CAS testing code. Keeping the code here also minimizes
- // the impact on the common case fast path code.
-
- if (new_obj == NULL) {
- _old_gen_is_full = true;
- return oop_promotion_failed(o, test_mark);
- }
- }
- }
-
- assert(new_obj != NULL, "allocation should have succeeded");
-
- // Copy obj
- Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
-
- // Now we have to CAS in the header.
- if (o->cas_forward_to(new_obj, test_mark)) {
- // We won any races, we "own" this object.
- assert(new_obj == o->forwardee(), "Sanity");
-
- // Increment age if obj still in new generation. Now that
- // we're dealing with a markOop that cannot change, it is
- // okay to use the non mt safe oop methods.
- if (!new_obj_is_tenured) {
- new_obj->incr_age();
- assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
- }
-
- // Do the size comparison first with new_obj_size, which we
- // already have. Hopefully, only a few objects are larger than
- // _min_array_size_for_chunking, and most of them will be arrays.
- // So, the is->objArray() test would be very infrequent.
- if (new_obj_size > _min_array_size_for_chunking &&
- new_obj->is_objArray() &&
- PSChunkLargeArrays) {
- // we'll chunk it
- oop* const masked_o = mask_chunked_array_oop(o);
- push_depth(masked_o);
- TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
- } else {
- // we'll just push its contents
- new_obj->push_contents(this);
- }
- } else {
- // We lost, someone else "owns" this object
- guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
-
- // Try to deallocate the space. If it was directly allocated we cannot
- // deallocate it, so we have to test. If the deallocation fails,
- // overwrite with a filler object.
- if (new_obj_is_tenured) {
- if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
- CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
- }
- } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
- CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
- }
-
- // don't update this before the unallocation!
- new_obj = o->forwardee();
- }
- } else {
- assert(o->is_forwarded(), "Sanity");
- new_obj = o->forwardee();
- }
-
-#ifdef DEBUG
- // This code must come after the CAS test, or it will print incorrect
- // information.
- if (TraceScavenge) {
- gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (" SIZE_FORMAT ")}",
- PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
- new_obj->blueprint()->internal_name(), o, new_obj, new_obj->size());
- }
-#endif
-
- return new_obj;
-}
-
template <class T> void PSPromotionManager::process_array_chunk_work(
oop obj,
int start, int end) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.hpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.hpp Fri Feb 10 17:40:20 2012 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2012, 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
@@ -171,7 +171,7 @@
void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
// Promotion methods
- oop copy_to_survivor_space(oop o);
+ template<bool promote_immediately> oop copy_to_survivor_space(oop o);
oop oop_promotion_failed(oop obj, markOop obj_mark);
void reset();
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.inline.hpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.inline.hpp Fri Feb 10 17:40:20 2012 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2012, 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
@@ -61,6 +61,170 @@
claim_or_forward_internal_depth(p);
}
+//
+// This method is pretty bulky. It would be nice to split it up
+// into smaller submethods, but we need to be careful not to hurt
+// performance.
+//
+template<bool promote_immediately>
+oop PSPromotionManager::copy_to_survivor_space(oop o) {
+ assert(PSScavenge::should_scavenge(&o), "Sanity");
+
+ oop new_obj = NULL;
+
+ // NOTE! We must be very careful with any methods that access the mark
+ // in o. There may be multiple threads racing on it, and it may be forwarded
+ // at any time. Do not use oop methods for accessing the mark!
+ markOop test_mark = o->mark();
+
+ // The same test as "o->is_forwarded()"
+ if (!test_mark->is_marked()) {
+ bool new_obj_is_tenured = false;
+ size_t new_obj_size = o->size();
+
+ if (!promote_immediately) {
+ // Find the objects age, MT safe.
+ int age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
+ test_mark->displaced_mark_helper()->age() : test_mark->age();
+
+ // Try allocating obj in to-space (unless too old)
+ if (age < PSScavenge::tenuring_threshold()) {
+ new_obj = (oop) _young_lab.allocate(new_obj_size);
+ if (new_obj == NULL && !_young_gen_is_full) {
+ // Do we allocate directly, or flush and refill?
+ if (new_obj_size > (YoungPLABSize / 2)) {
+ // Allocate this object directly
+ new_obj = (oop)young_space()->cas_allocate(new_obj_size);
+ } else {
+ // Flush and fill
+ _young_lab.flush();
+
+ HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
+ if (lab_base != NULL) {
+ _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
+ // Try the young lab allocation again.
+ new_obj = (oop) _young_lab.allocate(new_obj_size);
+ } else {
+ _young_gen_is_full = true;
+ }
+ }
+ }
+ }
+ }
+
+ // Otherwise try allocating obj tenured
+ if (new_obj == NULL) {
+#ifndef PRODUCT
+ if (Universe::heap()->promotion_should_fail()) {
+ return oop_promotion_failed(o, test_mark);
+ }
+#endif // #ifndef PRODUCT
+
+ new_obj = (oop) _old_lab.allocate(new_obj_size);
+ new_obj_is_tenured = true;
+
+ if (new_obj == NULL) {
+ if (!_old_gen_is_full) {
+ // Do we allocate directly, or flush and refill?
+ if (new_obj_size > (OldPLABSize / 2)) {
+ // Allocate this object directly
+ new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
+ } else {
+ // Flush and fill
+ _old_lab.flush();
+
+ HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
+ if(lab_base != NULL) {
+ _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
+ // Try the old lab allocation again.
+ new_obj = (oop) _old_lab.allocate(new_obj_size);
+ }
+ }
+ }
+
+ // This is the promotion failed test, and code handling.
+ // The code belongs here for two reasons. It is slightly
+ // different thatn the code below, and cannot share the
+ // CAS testing code. Keeping the code here also minimizes
+ // the impact on the common case fast path code.
+
+ if (new_obj == NULL) {
+ _old_gen_is_full = true;
+ return oop_promotion_failed(o, test_mark);
+ }
+ }
+ }
+
+ assert(new_obj != NULL, "allocation should have succeeded");
+
+ // Copy obj
+ Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
+
+ // Now we have to CAS in the header.
+ if (o->cas_forward_to(new_obj, test_mark)) {
+ // We won any races, we "own" this object.
+ assert(new_obj == o->forwardee(), "Sanity");
+
+ // Increment age if obj still in new generation. Now that
+ // we're dealing with a markOop that cannot change, it is
+ // okay to use the non mt safe oop methods.
+ if (!new_obj_is_tenured) {
+ new_obj->incr_age();
+ assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
+ }
+
+ // Do the size comparison first with new_obj_size, which we
+ // already have. Hopefully, only a few objects are larger than
+ // _min_array_size_for_chunking, and most of them will be arrays.
+ // So, the is->objArray() test would be very infrequent.
+ if (new_obj_size > _min_array_size_for_chunking &&
+ new_obj->is_objArray() &&
+ PSChunkLargeArrays) {
+ // we'll chunk it
+ oop* const masked_o = mask_chunked_array_oop(o);
+ push_depth(masked_o);
+ TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
+ } else {
+ // we'll just push its contents
+ new_obj->push_contents(this);
+ }
+ } else {
+ // We lost, someone else "owns" this object
+ guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
+
+ // Try to deallocate the space. If it was directly allocated we cannot
+ // deallocate it, so we have to test. If the deallocation fails,
+ // overwrite with a filler object.
+ if (new_obj_is_tenured) {
+ if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
+ CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
+ }
+ } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
+ CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
+ }
+
+ // don't update this before the unallocation!
+ new_obj = o->forwardee();
+ }
+ } else {
+ assert(o->is_forwarded(), "Sanity");
+ new_obj = o->forwardee();
+ }
+
+#ifdef DEBUG
+ // This code must come after the CAS test, or it will print incorrect
+ // information.
+ if (TraceScavenge) {
+ gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (" SIZE_FORMAT ")}",
+ PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
+ new_obj->blueprint()->internal_name(), o, new_obj, new_obj->size());
+ }
+#endif
+
+ return new_obj;
+}
+
+
inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
if (is_oop_masked(p)) {
assert(PSChunkLargeArrays, "invariant");
@@ -69,9 +233,9 @@
} else {
if (p.is_narrow()) {
assert(UseCompressedOops, "Error");
- PSScavenge::copy_and_push_safe_barrier(this, (narrowOop*)p);
+ PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
} else {
- PSScavenge::copy_and_push_safe_barrier(this, (oop*)p);
+ PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
}
}
}
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Fri Feb 10 17:40:20 2012 -0800
@@ -24,6 +24,7 @@
#include "precompiled.hpp"
#include "classfile/symbolTable.hpp"
+#include "code/codeCache.hpp"
#include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
#include "gc_implementation/parallelScavenge/gcTaskManager.hpp"
#include "gc_implementation/parallelScavenge/generationSizer.hpp"
@@ -100,7 +101,7 @@
// Weak refs may be visited more than once.
if (PSScavenge::should_scavenge(p, _to_space)) {
- PSScavenge::copy_and_push_safe_barrier(_promotion_manager, p);
+ PSScavenge::copy_and_push_safe_barrier<T, /*promote_immediately=*/false>(_promotion_manager, p);
}
}
virtual void do_oop(oop* p) { PSKeepAliveClosure::do_oop_work(p); }
@@ -602,6 +603,8 @@
NOT_PRODUCT(reference_processor()->verify_no_references_recorded());
+ CodeCache::prune_scavenge_root_nmethods();
+
// Re-verify object start arrays
if (VerifyObjectStartArray &&
VerifyAfterGC) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp Fri Feb 10 17:40:20 2012 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2012, 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
@@ -135,7 +135,8 @@
template <class T> static inline bool should_scavenge(T* p, MutableSpace* to_space);
template <class T> static inline bool should_scavenge(T* p, bool check_to_space);
- template <class T> inline static void copy_and_push_safe_barrier(PSPromotionManager* pm, T* p);
+ template <class T, bool promote_immediately>
+ inline static void copy_and_push_safe_barrier(PSPromotionManager* pm, T* p);
// Is an object in the young generation
// This assumes that the HeapWord argument is in the heap,
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.inline.hpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.inline.hpp Fri Feb 10 17:40:20 2012 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2012, 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
@@ -28,6 +28,7 @@
#include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
#include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
+#include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.hpp"
inline void PSScavenge::save_to_space_top_before_gc() {
@@ -65,7 +66,7 @@
// Attempt to "claim" oop at p via CAS, push the new obj if successful
// This version tests the oop* to make sure it is within the heap before
// attempting marking.
-template <class T>
+template <class T, bool promote_immediately>
inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm,
T* p) {
assert(should_scavenge(p, true), "revisiting object?");
@@ -73,7 +74,7 @@
oop o = oopDesc::load_decode_heap_oop_not_null(p);
oop new_obj = o->is_forwarded()
? o->forwardee()
- : pm->copy_to_survivor_space(o);
+ : pm->copy_to_survivor_space<promote_immediately>(o);
oopDesc::encode_store_heap_oop_not_null(p, new_obj);
// We cannot mark without test, as some code passes us pointers
@@ -86,7 +87,8 @@
}
}
-class PSScavengeRootsClosure: public OopClosure {
+template<bool promote_immediately>
+class PSRootsClosure: public OopClosure {
private:
PSPromotionManager* _promotion_manager;
@@ -94,13 +96,16 @@
template <class T> void do_oop_work(T *p) {
if (PSScavenge::should_scavenge(p)) {
// We never card mark roots, maybe call a func without test?
- PSScavenge::copy_and_push_safe_barrier(_promotion_manager, p);
+ PSScavenge::copy_and_push_safe_barrier<T, promote_immediately>(_promotion_manager, p);
}
}
public:
- PSScavengeRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
- void do_oop(oop* p) { PSScavengeRootsClosure::do_oop_work(p); }
- void do_oop(narrowOop* p) { PSScavengeRootsClosure::do_oop_work(p); }
+ PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
+ void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
+ void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
};
+typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
+typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
+
#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.cpp Mon Feb 06 12:18:24 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.cpp Fri Feb 10 17:40:20 2012 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2012, 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
@@ -51,6 +51,7 @@
PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);
PSScavengeRootsClosure roots_closure(pm);
+ PSPromoteRootsClosure roots_to_old_closure(pm);
switch (_root_type) {
case universe:
@@ -91,7 +92,7 @@
case code_cache:
{
- CodeBlobToOopClosure each_scavengable_code_blob(&roots_closure, /*do_marking=*/ true);
+ CodeBlobToOopClosure each_scavengable_code_blob(&roots_to_old_closure, /*do_marking=*/ true);
CodeCache::scavenge_root_nmethods_do(&each_scavengable_code_blob);
}
break;