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6672698: mangle_unused_area() should not remangle the entire heap at each collection

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Maintain a high water mark for the allocations in a space and mangle only up to that high water mark.

Reviewed-by: ysr, apetrusenko
This commit is contained in:
Jon Masamitsu 2008-07-09 15:08:55 -07:00
parent 0d9452401c
commit 18dbebd143
43 changed files with 1299 additions and 206 deletions
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214
hotspot/src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp
View file

@ -36,7 +36,7 @@ PSYoungGen::PSYoungGen(size_t initial_size,
void PSYoungGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) {
assert(_init_gen_size != 0, "Should have a finite size");
_virtual_space = new PSVirtualSpace(rs, alignment);
if (!_virtual_space->expand_by(_init_gen_size)) {
if (!virtual_space()->expand_by(_init_gen_size)) {
vm_exit_during_initialization("Could not reserve enough space for "
"object heap");
}
@ -49,13 +49,20 @@ void PSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
void PSYoungGen::initialize_work() {
_reserved = MemRegion((HeapWord*)_virtual_space->low_boundary(),
(HeapWord*)_virtual_space->high_boundary());
_reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
(HeapWord*)virtual_space()->high_boundary());
MemRegion cmr((HeapWord*)_virtual_space->low(),
(HeapWord*)_virtual_space->high());
MemRegion cmr((HeapWord*)virtual_space()->low(),
(HeapWord*)virtual_space()->high());
Universe::heap()->barrier_set()->resize_covered_region(cmr);
if (ZapUnusedHeapArea) {
// Mangle newly committed space immediately because it
// can be done here more simply that after the new
// spaces have been computed.
SpaceMangler::mangle_region(cmr);
}
if (UseNUMA) {
_eden_space = new MutableNUMASpace();
} else {
@ -89,7 +96,7 @@ void PSYoungGen::initialize_work() {
// Compute maximum space sizes for performance counters
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
size_t alignment = heap->intra_heap_alignment();
size_t size = _virtual_space->reserved_size();
size_t size = virtual_space()->reserved_size();
size_t max_survivor_size;
size_t max_eden_size;
@ -142,7 +149,7 @@ void PSYoungGen::compute_initial_space_boundaries() {
// Compute sizes
size_t alignment = heap->intra_heap_alignment();
size_t size = _virtual_space->committed_size();
size_t size = virtual_space()->committed_size();
size_t survivor_size = size / InitialSurvivorRatio;
survivor_size = align_size_down(survivor_size, alignment);
@ -164,18 +171,18 @@ void PSYoungGen::compute_initial_space_boundaries() {
}
void PSYoungGen::set_space_boundaries(size_t eden_size, size_t survivor_size) {
assert(eden_size < _virtual_space->committed_size(), "just checking");
assert(eden_size < virtual_space()->committed_size(), "just checking");
assert(eden_size > 0 && survivor_size > 0, "just checking");
// Initial layout is Eden, to, from. After swapping survivor spaces,
// that leaves us with Eden, from, to, which is step one in our two
// step resize-with-live-data procedure.
char *eden_start = _virtual_space->low();
char *eden_start = virtual_space()->low();
char *to_start = eden_start + eden_size;
char *from_start = to_start + survivor_size;
char *from_end = from_start + survivor_size;
assert(from_end == _virtual_space->high(), "just checking");
assert(from_end == virtual_space()->high(), "just checking");
assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
assert(is_object_aligned((intptr_t)to_start), "checking alignment");
assert(is_object_aligned((intptr_t)from_start), "checking alignment");
@ -184,9 +191,9 @@ void PSYoungGen::set_space_boundaries(size_t eden_size, size_t survivor_size) {
MemRegion to_mr ((HeapWord*)to_start, (HeapWord*)from_start);
MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
eden_space()->initialize(eden_mr, true);
to_space()->initialize(to_mr , true);
from_space()->initialize(from_mr, true);
eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
to_space()->initialize(to_mr , true, ZapUnusedHeapArea);
from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
}
#ifndef PRODUCT
@ -207,7 +214,7 @@ void PSYoungGen::space_invariants() {
char* to_start = (char*)to_space()->bottom();
char* to_end = (char*)to_space()->end();
guarantee(eden_start >= _virtual_space->low(), "eden bottom");
guarantee(eden_start >= virtual_space()->low(), "eden bottom");
guarantee(eden_start < eden_end, "eden space consistency");
guarantee(from_start < from_end, "from space consistency");
guarantee(to_start < to_end, "to space consistency");
@ -217,29 +224,29 @@ void PSYoungGen::space_invariants() {
// Eden, from, to
guarantee(eden_end <= from_start, "eden/from boundary");
guarantee(from_end <= to_start, "from/to boundary");
guarantee(to_end <= _virtual_space->high(), "to end");
guarantee(to_end <= virtual_space()->high(), "to end");
} else {
// Eden, to, from
guarantee(eden_end <= to_start, "eden/to boundary");
guarantee(to_end <= from_start, "to/from boundary");
guarantee(from_end <= _virtual_space->high(), "from end");
guarantee(from_end <= virtual_space()->high(), "from end");
}
// More checks that the virtual space is consistent with the spaces
assert(_virtual_space->committed_size() >=
assert(virtual_space()->committed_size() >=
(eden_space()->capacity_in_bytes() +
to_space()->capacity_in_bytes() +
from_space()->capacity_in_bytes()), "Committed size is inconsistent");
assert(_virtual_space->committed_size() <= _virtual_space->reserved_size(),
assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
"Space invariant");
char* eden_top = (char*)eden_space()->top();
char* from_top = (char*)from_space()->top();
char* to_top = (char*)to_space()->top();
assert(eden_top <= _virtual_space->high(), "eden top");
assert(from_top <= _virtual_space->high(), "from top");
assert(to_top <= _virtual_space->high(), "to top");
assert(eden_top <= virtual_space()->high(), "eden top");
assert(from_top <= virtual_space()->high(), "from top");
assert(to_top <= virtual_space()->high(), "to top");
_virtual_space->verify();
virtual_space()->verify();
}
#endif
@ -265,8 +272,8 @@ void PSYoungGen::resize(size_t eden_size, size_t survivor_size) {
bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
const size_t alignment = _virtual_space->alignment();
size_t orig_size = _virtual_space->committed_size();
const size_t alignment = virtual_space()->alignment();
size_t orig_size = virtual_space()->committed_size();
bool size_changed = false;
// There used to be this guarantee there.
@ -288,10 +295,18 @@ bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
// Grow the generation
size_t change = desired_size - orig_size;
assert(change % alignment == 0, "just checking");
if (!_virtual_space->expand_by(change)) {
HeapWord* prev_high = (HeapWord*) virtual_space()->high();
if (!virtual_space()->expand_by(change)) {
return false; // Error if we fail to resize!
}
if (ZapUnusedHeapArea) {
// Mangle newly committed space immediately because it
// can be done here more simply that after the new
// spaces have been computed.
HeapWord* new_high = (HeapWord*) virtual_space()->high();
MemRegion mangle_region(prev_high, new_high);
SpaceMangler::mangle_region(mangle_region);
}
size_changed = true;
} else if (desired_size < orig_size) {
size_t desired_change = orig_size - desired_size;
@ -321,19 +336,95 @@ bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
post_resize();
if (Verbose && PrintGC) {
size_t current_size = _virtual_space->committed_size();
size_t current_size = virtual_space()->committed_size();
gclog_or_tty->print_cr("PSYoung generation size changed: "
SIZE_FORMAT "K->" SIZE_FORMAT "K",
orig_size/K, current_size/K);
}
}
guarantee(eden_plus_survivors <= _virtual_space->committed_size() ||
_virtual_space->committed_size() == max_size(), "Sanity");
guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
virtual_space()->committed_size() == max_size(), "Sanity");
return true;
}
#ifndef PRODUCT
// In the numa case eden is not mangled so a survivor space
// moving into a region previously occupied by a survivor
// may find an unmangled region. Also in the PS case eden
// to-space and from-space may not touch (i.e., there may be
// gaps between them due to movement while resizing the
// spaces). Those gaps must be mangled.
void PSYoungGen::mangle_survivors(MutableSpace* s1,
MemRegion s1MR,
MutableSpace* s2,
MemRegion s2MR) {
// Check eden and gap between eden and from-space, in deciding
// what to mangle in from-space. Check the gap between from-space
// and to-space when deciding what to mangle.
//
// +--------+ +----+ +---+
// | eden | |s1 | |s2 |
// +--------+ +----+ +---+
// +-------+ +-----+
// |s1MR | |s2MR |
// +-------+ +-----+
// All of survivor-space is properly mangled so find the
// upper bound on the mangling for any portion above current s1.
HeapWord* delta_end = MIN2(s1->bottom(), s1MR.end());
MemRegion delta1_left;
if (s1MR.start() < delta_end) {
delta1_left = MemRegion(s1MR.start(), delta_end);
s1->mangle_region(delta1_left);
}
// Find any portion to the right of the current s1.
HeapWord* delta_start = MAX2(s1->end(), s1MR.start());
MemRegion delta1_right;
if (delta_start < s1MR.end()) {
delta1_right = MemRegion(delta_start, s1MR.end());
s1->mangle_region(delta1_right);
}
// Similarly for the second survivor space except that
// any of the new region that overlaps with the current
// region of the first survivor space has already been
// mangled.
delta_end = MIN2(s2->bottom(), s2MR.end());
delta_start = MAX2(s2MR.start(), s1->end());
MemRegion delta2_left;
if (s2MR.start() < delta_end) {
delta2_left = MemRegion(s2MR.start(), delta_end);
s2->mangle_region(delta2_left);
}
delta_start = MAX2(s2->end(), s2MR.start());
MemRegion delta2_right;
if (delta_start < s2MR.end()) {
s2->mangle_region(delta2_right);
}
if (TraceZapUnusedHeapArea) {
// s1
gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
s1->bottom(), s1->end(), s1MR.start(), s1MR.end());
gclog_or_tty->print_cr(" Mangle before: [" PTR_FORMAT ", "
PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
delta1_left.start(), delta1_left.end(), delta1_right.start(),
delta1_right.end());
// s2
gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
s2->bottom(), s2->end(), s2MR.start(), s2MR.end());
gclog_or_tty->print_cr(" Mangle before: [" PTR_FORMAT ", "
PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
delta2_left.start(), delta2_left.end(), delta2_right.start(),
delta2_right.end());
}
}
#endif // NOT PRODUCT
void PSYoungGen::resize_spaces(size_t requested_eden_size,
size_t requested_survivor_size) {
@ -396,9 +487,11 @@ void PSYoungGen::resize_spaces(size_t requested_eden_size,
const bool maintain_minimum =
(requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
bool eden_from_to_order = from_start < to_start;
// Check whether from space is below to space
if (from_start < to_start) {
if (eden_from_to_order) {
// Eden, from, to
eden_from_to_order = true;
if (PrintAdaptiveSizePolicy && Verbose) {
gclog_or_tty->print_cr(" Eden, from, to:");
}
@ -435,7 +528,7 @@ void PSYoungGen::resize_spaces(size_t requested_eden_size,
// extra calculations.
// First calculate an optimal to-space
to_end = (char*)_virtual_space->high();
to_end = (char*)virtual_space()->high();
to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
sizeof(char));
@ -491,7 +584,7 @@ void PSYoungGen::resize_spaces(size_t requested_eden_size,
// to space as if we were able to resize from space, even though from
// space is not modified.
// Giving eden priority was tried and gave poorer performance.
to_end = (char*)pointer_delta(_virtual_space->high(),
to_end = (char*)pointer_delta(virtual_space()->high(),
(char*)requested_survivor_size,
sizeof(char));
to_end = MIN2(to_end, from_start);
@ -560,9 +653,45 @@ void PSYoungGen::resize_spaces(size_t requested_eden_size,
size_t old_from = from_space()->capacity_in_bytes();
size_t old_to = to_space()->capacity_in_bytes();
eden_space()->initialize(edenMR, true);
to_space()->initialize(toMR , true);
from_space()->initialize(fromMR, false); // Note, not cleared!
if (ZapUnusedHeapArea) {
// NUMA is a special case because a numa space is not mangled
// in order to not prematurely bind its address to memory to
// the wrong memory (i.e., don't want the GC thread to first
// touch the memory). The survivor spaces are not numa
// spaces and are mangled.
if (UseNUMA) {
if (eden_from_to_order) {
mangle_survivors(from_space(), fromMR, to_space(), toMR);
} else {
mangle_survivors(to_space(), toMR, from_space(), fromMR);
}
}
// If not mangling the spaces, do some checking to verify that
// the spaces are already mangled.
// The spaces should be correctly mangled at this point so
// do some checking here. Note that they are not being mangled
// in the calls to initialize().
// Must check mangling before the spaces are reshaped. Otherwise,
// the bottom or end of one space may have moved into an area
// covered by another space and a failure of the check may
// not correctly indicate which space is not properly mangled.
HeapWord* limit = (HeapWord*) virtual_space()->high();
eden_space()->check_mangled_unused_area(limit);
from_space()->check_mangled_unused_area(limit);
to_space()->check_mangled_unused_area(limit);
}
// When an existing space is being initialized, it is not
// mangled because the space has been previously mangled.
eden_space()->initialize(edenMR,
SpaceDecorator::Clear,
SpaceDecorator::DontMangle);
to_space()->initialize(toMR,
SpaceDecorator::Clear,
SpaceDecorator::DontMangle);
from_space()->initialize(fromMR,
SpaceDecorator::DontClear,
SpaceDecorator::DontMangle);
assert(from_space()->top() == old_from_top, "from top changed!");
@ -671,7 +800,7 @@ void PSYoungGen::print_on(outputStream* st) const {
st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
capacity_in_bytes()/K, used_in_bytes()/K);
}
_virtual_space->print_space_boundaries_on(st);
virtual_space()->print_space_boundaries_on(st);
st->print(" eden"); eden_space()->print_on(st);
st->print(" from"); from_space()->print_on(st);
st->print(" to "); to_space()->print_on(st);
@ -774,7 +903,9 @@ void PSYoungGen::reset_survivors_after_shrink() {
// Was there a shrink of the survivor space?
if (new_end < space_shrinking->end()) {
MemRegion mr(space_shrinking->bottom(), new_end);
space_shrinking->initialize(mr, false /* clear */);
space_shrinking->initialize(mr,
SpaceDecorator::DontClear,
SpaceDecorator::Mangle);
}
}
@ -809,3 +940,12 @@ void PSYoungGen::verify(bool allow_dirty) {
from_space()->verify(allow_dirty);
to_space()->verify(allow_dirty);
}
#ifndef PRODUCT
void PSYoungGen::record_spaces_top() {
assert(ZapUnusedHeapArea, "Not mangling unused space");
eden_space()->set_top_for_allocations();
from_space()->set_top_for_allocations();
to_space()->set_top_for_allocations();
}
#endif