Mercurial > hg > graal-compiler
diff src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp @ 263:12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
Summary: Maintain a high water mark for the allocations in a space and mangle only up to that high water mark.
Reviewed-by: ysr, apetrusenko
author | jmasa |
---|---|
date | Wed, 09 Jul 2008 15:08:55 -0700 |
parents | 183f41cf8bfe |
children | 850fdf70db2b |
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--- a/src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp Fri Jun 27 19:12:11 2008 -0700 +++ b/src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp Wed Jul 09 15:08:55 2008 -0700 @@ -170,9 +170,20 @@ if (desired_size > orig_size) { // Grow the generation size_t change = desired_size - orig_size; + HeapWord* prev_low = (HeapWord*) virtual_space()->low(); if (!virtual_space()->expand_by(change)) { return false; } + 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_low = (HeapWord*) virtual_space()->low(); + assert(new_low < prev_low, "Did not grow"); + + MemRegion mangle_region(new_low, prev_low); + SpaceMangler::mangle_region(mangle_region); + } size_changed = true; } else if (desired_size < orig_size) { size_t desired_change = orig_size - desired_size; @@ -215,8 +226,10 @@ // current implementation does not allow holes between the spaces // _young_generation_boundary has to be reset because it changes. // so additional verification + void ASPSYoungGen::resize_spaces(size_t requested_eden_size, size_t requested_survivor_size) { + assert(UseAdaptiveSizePolicy, "sanity check"); assert(requested_eden_size > 0 && requested_survivor_size > 0, "just checking"); @@ -276,22 +289,42 @@ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); const size_t alignment = heap->intra_heap_alignment(); + 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 + if (PrintAdaptiveSizePolicy && Verbose) { gclog_or_tty->print_cr(" Eden, from, to:"); } // Set eden - // Compute how big eden can be, then adjust end. - // See comment in PSYoungGen::resize_spaces() on - // calculating eden_end. - const size_t eden_size = MIN2(requested_eden_size, - pointer_delta(from_start, - eden_start, - sizeof(char))); + // "requested_eden_size" is a goal for the size of eden + // and may not be attainable. "eden_size" below is + // calculated based on the location of from-space and + // the goal for the size of eden. from-space is + // fixed in place because it contains live data. + // The calculation is done this way to avoid 32bit + // overflow (i.e., eden_start + requested_eden_size + // may too large for representation in 32bits). + size_t eden_size; + if (maintain_minimum) { + // Only make eden larger than the requested size if + // the minimum size of the generation has to be maintained. + // This could be done in general but policy at a higher + // level is determining a requested size for eden and that + // should be honored unless there is a fundamental reason. + eden_size = pointer_delta(from_start, + eden_start, + sizeof(char)); + } else { + eden_size = MIN2(requested_eden_size, + pointer_delta(from_start, eden_start, sizeof(char))); + } + eden_end = eden_start + eden_size; assert(eden_end >= eden_start, "addition overflowed") @@ -371,12 +404,14 @@ to_start = MAX2(to_start, eden_start + alignment); // Compute how big eden can be, then adjust end. - // See comment in PSYoungGen::resize_spaces() on - // calculating eden_end. - const size_t eden_size = MIN2(requested_eden_size, - pointer_delta(to_start, - eden_start, - sizeof(char))); + // See comments above on calculating eden_end. + size_t eden_size; + if (maintain_minimum) { + eden_size = pointer_delta(to_start, eden_start, sizeof(char)); + } else { + eden_size = MIN2(requested_eden_size, + pointer_delta(to_start, eden_start, sizeof(char))); + } eden_end = eden_start + eden_size; assert(eden_end >= eden_start, "addition overflowed") @@ -423,9 +458,47 @@ 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); + PSScavenge::set_young_generation_boundary(eden_space()->bottom()); assert(from_space()->top() == old_from_top, "from top changed!"); @@ -446,7 +519,6 @@ } space_invariants(); } - void ASPSYoungGen::reset_after_change() { assert_locked_or_safepoint(Heap_lock); @@ -458,7 +530,9 @@ HeapWord* eden_bottom = eden_space()->bottom(); if (new_eden_bottom != eden_bottom) { MemRegion eden_mr(new_eden_bottom, eden_space()->end()); - eden_space()->initialize(eden_mr, true); + eden_space()->initialize(eden_mr, + SpaceDecorator::Clear, + SpaceDecorator::Mangle); PSScavenge::set_young_generation_boundary(eden_space()->bottom()); } MemRegion cmr((HeapWord*)virtual_space()->low(),