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src/share/vm/gc_implementation/shared/mutableNUMASpace.hpp@a61af66fc99e (annotated)

src/share/vm/gc_implementation/shared/mutableNUMASpace.hpp

Sat, 01 Dec 2007 00:00:00 +0000

author

duke

date

Sat, 01 Dec 2007 00:00:00 +0000

changeset 435

a61af66fc99e

child 576

fcbfc50865ab

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duke@435	1	/*
duke@435	2	* Copyright 2006-2007 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	/*
duke@435	26	* The NUMA-aware allocator (MutableNUMASpace) is basically a modification
duke@435	27	* of MutableSpace which preserves interfaces but implements different
duke@435	28	* functionality. The space is split into chunks for each locality group
duke@435	29	* (resizing for adaptive size policy is also supported). For each thread
duke@435	30	* allocations are performed in the chunk corresponding to the home locality
duke@435	31	* group of the thread. Whenever any chunk fills-in the young generation
duke@435	32	* collection occurs.
duke@435	33	* The chunks can be also be adaptively resized. The idea behind the adaptive
duke@435	34	* sizing is to reduce the loss of the space in the eden due to fragmentation.
duke@435	35	* The main cause of fragmentation is uneven allocation rates of threads.
duke@435	36	* The allocation rate difference between locality groups may be caused either by
duke@435	37	* application specifics or by uneven LWP distribution by the OS. Besides,
duke@435	38	* application can have less threads then the number of locality groups.
duke@435	39	* In order to resize the chunk we measure the allocation rate of the
duke@435	40	* application between collections. After that we reshape the chunks to reflect
duke@435	41	* the allocation rate pattern. The AdaptiveWeightedAverage exponentially
duke@435	42	* decaying average is used to smooth the measurements. The NUMASpaceResizeRate
duke@435	43	* parameter is used to control the adaptation speed by restricting the number of
duke@435	44	* bytes that can be moved during the adaptation phase.
duke@435	45	* Chunks may contain pages from a wrong locality group. The page-scanner has
duke@435	46	* been introduced to address the problem. Remote pages typically appear due to
duke@435	47	* the memory shortage in the target locality group. Besides Solaris would
duke@435	48	* allocate a large page from the remote locality group even if there are small
duke@435	49	* local pages available. The page-scanner scans the pages right after the
duke@435	50	* collection and frees remote pages in hope that subsequent reallocation would
duke@435	51	* be more successful. This approach proved to be useful on systems with high
duke@435	52	* load where multiple processes are competing for the memory.
duke@435	53	*/
duke@435	54
duke@435	55	class MutableNUMASpace : public MutableSpace {
duke@435	56	friend class VMStructs;
duke@435	57
duke@435	58	class LGRPSpace : public CHeapObj {
duke@435	59	int _lgrp_id;
duke@435	60	MutableSpace* _space;
duke@435	61	MemRegion _invalid_region;
duke@435	62	AdaptiveWeightedAverage *_alloc_rate;
duke@435	63
duke@435	64	struct SpaceStats {
duke@435	65	size_t _local_space, _remote_space, _unbiased_space, _uncommited_space;
duke@435	66	size_t _large_pages, _small_pages;
duke@435	67
duke@435	68	SpaceStats() {
duke@435	69	_local_space = 0;
duke@435	70	_remote_space = 0;
duke@435	71	_unbiased_space = 0;
duke@435	72	_uncommited_space = 0;
duke@435	73	_large_pages = 0;
duke@435	74	_small_pages = 0;
duke@435	75	}
duke@435	76	};
duke@435	77
duke@435	78	SpaceStats _space_stats;
duke@435	79
duke@435	80	char* _last_page_scanned;
duke@435	81	char* last_page_scanned() { return _last_page_scanned; }
duke@435	82	void set_last_page_scanned(char* p) { _last_page_scanned = p; }
duke@435	83	public:
duke@435	84	LGRPSpace(int l) : _lgrp_id(l), _last_page_scanned(NULL) {
duke@435	85	_space = new MutableSpace();
duke@435	86	_alloc_rate = new AdaptiveWeightedAverage(NUMAChunkResizeWeight);
duke@435	87	}
duke@435	88	~LGRPSpace() {
duke@435	89	delete _space;
duke@435	90	delete _alloc_rate;
duke@435	91	}
duke@435	92
duke@435	93	void add_invalid_region(MemRegion r) {
duke@435	94	if (!_invalid_region.is_empty()) {
duke@435	95	_invalid_region.set_start(MIN2(_invalid_region.start(), r.start()));
duke@435	96	_invalid_region.set_end(MAX2(_invalid_region.end(), r.end()));
duke@435	97	} else {
duke@435	98	_invalid_region = r;
duke@435	99	}
duke@435	100	}
duke@435	101
duke@435	102	static bool equals(void* lgrp_id_value, LGRPSpace* p) {
duke@435	103	return *(int*)lgrp_id_value == p->lgrp_id();
duke@435	104	}
duke@435	105
duke@435	106	void sample() {
duke@435	107	alloc_rate()->sample(space()->used_in_bytes());
duke@435	108	}
duke@435	109
duke@435	110	MemRegion invalid_region() const { return _invalid_region; }
duke@435	111	void set_invalid_region(MemRegion r) { _invalid_region = r; }
duke@435	112	int lgrp_id() const { return _lgrp_id; }
duke@435	113	MutableSpace* space() const { return _space; }
duke@435	114	AdaptiveWeightedAverage* alloc_rate() const { return _alloc_rate; }
duke@435	115	SpaceStats* space_stats() { return &_space_stats; }
duke@435	116	void clear_space_stats() { _space_stats = SpaceStats(); }
duke@435	117
duke@435	118	void accumulate_statistics(size_t page_size);
duke@435	119	void scan_pages(size_t page_size, size_t page_count);
duke@435	120	};
duke@435	121
duke@435	122	GrowableArray<LGRPSpace*>* _lgrp_spaces;
duke@435	123	size_t _page_size;
duke@435	124	unsigned _adaptation_cycles, _samples_count;
duke@435	125
duke@435	126	void set_page_size(size_t psz) { _page_size = psz; }
duke@435	127	size_t page_size() const { return _page_size; }
duke@435	128
duke@435	129	unsigned adaptation_cycles() { return _adaptation_cycles; }
duke@435	130	void set_adaptation_cycles(int v) { _adaptation_cycles = v; }
duke@435	131
duke@435	132	unsigned samples_count() { return _samples_count; }
duke@435	133	void increment_samples_count() { ++_samples_count; }
duke@435	134
duke@435	135	size_t _base_space_size;
duke@435	136	void set_base_space_size(size_t v) { _base_space_size = v; }
duke@435	137	size_t base_space_size() const { return _base_space_size; }
duke@435	138
duke@435	139	// Check if the NUMA topology has changed. Add and remove spaces if needed.
duke@435	140	// The update can be forced by setting the force parameter equal to true.
duke@435	141	bool update_layout(bool force);
duke@435	142	// Bias region towards the first-touching lgrp.
duke@435	143	void bias_region(MemRegion mr);
duke@435	144	// Free pages in a given region.
duke@435	145	void free_region(MemRegion mr);
duke@435	146	// Get current chunk size.
duke@435	147	size_t current_chunk_size(int i);
duke@435	148	// Get default chunk size (equally divide the space).
duke@435	149	size_t default_chunk_size();
duke@435	150	// Adapt the chunk size to follow the allocation rate.
duke@435	151	size_t adaptive_chunk_size(int i, size_t limit);
duke@435	152	// Scan and free invalid pages.
duke@435	153	void scan_pages(size_t page_count);
duke@435	154	// Return the bottom_region and the top_region. Align them to page_size() boundary.
duke@435	155	// |------------------new_region---------------------------------|
duke@435	156	// |----bottom_region--|---intersection---|------top_region------|
duke@435	157	void select_tails(MemRegion new_region, MemRegion intersection,
duke@435	158	MemRegion* bottom_region, MemRegion *top_region);
duke@435	159	// Try to merge the invalid region with the bottom or top region by decreasing
duke@435	160	// the intersection area. Return the invalid_region aligned to the page_size()
duke@435	161	// boundary if it's inside the intersection. Return non-empty invalid_region
duke@435	162	// if it lies inside the intersection (also page-aligned).
duke@435	163	// |------------------new_region---------------------------------|
duke@435	164	// |----------------|-------invalid---|--------------------------|
duke@435	165	// |----bottom_region--|---intersection---|------top_region------|
duke@435	166	void merge_regions(MemRegion new_region, MemRegion* intersection,
duke@435	167	MemRegion *invalid_region);
duke@435	168
duke@435	169	public:
duke@435	170	GrowableArray<LGRPSpace*>* lgrp_spaces() const { return _lgrp_spaces; }
duke@435	171	MutableNUMASpace();
duke@435	172	virtual ~MutableNUMASpace();
duke@435	173	// Space initialization.
duke@435	174	virtual void initialize(MemRegion mr, bool clear_space);
duke@435	175	// Update space layout if necessary. Do all adaptive resizing job.
duke@435	176	virtual void update();
duke@435	177	// Update allocation rate averages.
duke@435	178	virtual void accumulate_statistics();
duke@435	179
duke@435	180	virtual void clear();
duke@435	181	virtual void mangle_unused_area();
duke@435	182	virtual void ensure_parsability();
duke@435	183	virtual size_t used_in_words() const;
duke@435	184	virtual size_t free_in_words() const;
duke@435	185	virtual size_t tlab_capacity(Thread* thr) const;
duke@435	186	virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
duke@435	187
duke@435	188	// Allocation (return NULL if full)
duke@435	189	virtual HeapWord* allocate(size_t word_size);
duke@435	190	virtual HeapWord* cas_allocate(size_t word_size);
duke@435	191
duke@435	192	// Debugging
duke@435	193	virtual void print_on(outputStream* st) const;
duke@435	194	virtual void print_short_on(outputStream* st) const;
duke@435	195	virtual void verify(bool allow_dirty) const;
duke@435	196
duke@435	197	virtual void set_top(HeapWord* value);
duke@435	198	};