提交 5f3747f4 编写于 作者: J jcoomes

6330863: vm/gc/InfiniteList.java fails intermittently due to timeout

Summary: in some cases, allocate from the old gen before doing a full gc
Reviewed-by: stefank, jmasa
上级 7830f2dd
/*
* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2001, 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
......@@ -418,25 +418,17 @@ HeapWord* ParallelScavengeHeap::mem_allocate(
gc_count = Universe::heap()->total_collections();
result = young_gen()->allocate(size);
// (1) If the requested object is too large to easily fit in the
// young_gen, or
// (2) If GC is locked out via GCLocker, young gen is full and
// the need for a GC already signalled to GCLocker (done
// at a safepoint),
// ... then, rather than force a safepoint and (a potentially futile)
// collection (attempt) for each allocation, try allocation directly
// in old_gen. For case (2) above, we may in the future allow
// TLAB allocation directly in the old gen.
if (result != NULL) {
return result;
}
if (size >= (young_gen()->eden_space()->capacity_in_words(Thread::current()) / 2)) {
result = old_gen()->allocate(size);
if (result != NULL) {
return result;
}
// If certain conditions hold, try allocating from the old gen.
result = mem_allocate_old_gen(size);
if (result != NULL) {
return result;
}
// Failed to allocate without a gc.
if (GC_locker::is_active_and_needs_gc()) {
// If this thread is not in a jni critical section, we stall
// the requestor until the critical section has cleared and
......@@ -460,7 +452,6 @@ HeapWord* ParallelScavengeHeap::mem_allocate(
}
if (result == NULL) {
// Generate a VM operation
VM_ParallelGCFailedAllocation op(size, gc_count);
VMThread::execute(&op);
......@@ -523,6 +514,42 @@ HeapWord* ParallelScavengeHeap::mem_allocate(
return result;
}
// A "death march" is a series of ultra-slow allocations in which a full gc is
// done before each allocation, and after the full gc the allocation still
// cannot be satisfied from the young gen. This routine detects that condition;
// it should be called after a full gc has been done and the allocation
// attempted from the young gen. The parameter 'addr' should be the result of
// that young gen allocation attempt.
void
ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
if (addr != NULL) {
_death_march_count = 0; // death march has ended
} else if (_death_march_count == 0) {
if (should_alloc_in_eden(size)) {
_death_march_count = 1; // death march has started
}
}
}
HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) {
// Size is too big for eden, or gc is locked out.
return old_gen()->allocate(size);
}
// If a "death march" is in progress, allocate from the old gen a limited
// number of times before doing a GC.
if (_death_march_count > 0) {
if (_death_march_count < 64) {
++_death_march_count;
return old_gen()->allocate(size);
} else {
_death_march_count = 0;
}
}
return NULL;
}
// Failed allocation policy. Must be called from the VM thread, and
// only at a safepoint! Note that this method has policy for allocation
// flow, and NOT collection policy. So we do not check for gc collection
......@@ -535,27 +562,22 @@ HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
assert(!Universe::heap()->is_gc_active(), "not reentrant");
assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
size_t mark_sweep_invocation_count = total_invocations();
// We assume (and assert!) that an allocation at this point will fail
// unless we collect.
// We assume that allocation in eden will fail unless we collect.
// First level allocation failure, scavenge and allocate in young gen.
GCCauseSetter gccs(this, GCCause::_allocation_failure);
PSScavenge::invoke();
const bool invoked_full_gc = PSScavenge::invoke();
HeapWord* result = young_gen()->allocate(size);
// Second level allocation failure.
// Mark sweep and allocate in young generation.
if (result == NULL) {
// There is some chance the scavenge method decided to invoke mark_sweep.
// Don't mark sweep twice if so.
if (mark_sweep_invocation_count == total_invocations()) {
invoke_full_gc(false);
result = young_gen()->allocate(size);
}
if (result == NULL && !invoked_full_gc) {
invoke_full_gc(false);
result = young_gen()->allocate(size);
}
death_march_check(result, size);
// Third level allocation failure.
// After mark sweep and young generation allocation failure,
// allocate in old generation.
......
/*
* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2001, 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
......@@ -64,6 +64,7 @@ class ParallelScavengeHeap : public CollectedHeap {
// Collection of generations that are adjacent in the
// space reserved for the heap.
AdjoiningGenerations* _gens;
unsigned int _death_march_count;
static GCTaskManager* _gc_task_manager; // The task manager.
......@@ -71,8 +72,13 @@ class ParallelScavengeHeap : public CollectedHeap {
static inline size_t total_invocations();
HeapWord* allocate_new_tlab(size_t size);
inline bool should_alloc_in_eden(size_t size) const;
inline void death_march_check(HeapWord* const result, size_t size);
HeapWord* mem_allocate_old_gen(size_t size);
public:
ParallelScavengeHeap() : CollectedHeap() {
_death_march_count = 0;
set_alignment(_perm_gen_alignment, intra_heap_alignment());
set_alignment(_young_gen_alignment, intra_heap_alignment());
set_alignment(_old_gen_alignment, intra_heap_alignment());
......
/*
* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2006, 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
......@@ -36,6 +36,12 @@ inline size_t ParallelScavengeHeap::total_invocations()
PSMarkSweep::total_invocations();
}
inline bool ParallelScavengeHeap::should_alloc_in_eden(const size_t size) const
{
const size_t eden_size = young_gen()->eden_space()->capacity_in_words();
return size < eden_size / 2;
}
inline void ParallelScavengeHeap::invoke_scavenge()
{
PSScavenge::invoke();
......
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