本実装修正: - tiny_region_id_write_header() を追加: USER pointer を正しく返す - TLS slot からの segment 探索 (page_meta_of) - Page-level allocation で segment 再利用 - 2MiB alignment 保証 (4MiB 確保 + alignment) - free パスの route 修正 (v4 から v5 への fallthrough 削除) 動作確認: - SEGV 消失: alloc/free 基本動作 OK - 性能: ~18-20M ops/s (baseline 43-47M の約 40-45%) - 回帰原因: TLS slot 線形探索 O(n)、find_page O(n) 残タスク: - O(1) segment lookup 最適化 (hash または array 直接参照) - find_page 除去 (segment lookup 成功時) - partial_count/list 管理の最適化 ENV デフォルト OFF なので本線影響なし。 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
78 lines
3.2 KiB
C
78 lines
3.2 KiB
C
// smallsegment_v5_box.h - SmallSegment v5(Phase v5-0)
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//
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// 2MiB Segment / 64KiB Page ベースの O(1) page_meta lookup
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#ifndef HAKMEM_SMALLSEGMENT_V5_BOX_H
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#define HAKMEM_SMALLSEGMENT_V5_BOX_H
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#include <stdint.h>
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#include "smallobject_hotbox_v5_box.h"
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#define SMALL_SEGMENT_V5_SIZE (2 * 1024 * 1024) // 2 MiB
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#define SMALL_SEGMENT_V5_PAGE_SIZE (64 * 1024) // 64 KiB
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#define SMALL_SEGMENT_V5_NUM_PAGES (SMALL_SEGMENT_V5_SIZE / SMALL_SEGMENT_V5_PAGE_SIZE) // 32
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#define SMALL_SEGMENT_V5_MAGIC 0xDEADBEEF
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#define SMALL_SEGMENT_V5_PAGE_SHIFT 16 // log2(64KiB)
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// ポインタマクロ - O(1) segment/page 計算
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// SMALL_SEGMENT_V5_BASE_FROM_PTR(ptr) - ptr から segment base を mask で計算
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#define SMALL_SEGMENT_V5_BASE_FROM_PTR(ptr) \
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((SmallSegmentV5*)((uintptr_t)(ptr) & ~(SMALL_SEGMENT_V5_SIZE - 1)))
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// SMALL_SEGMENT_V5_PAGE_IDX(seg, ptr) - segment 内の page_idx を shift で計算
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#define SMALL_SEGMENT_V5_PAGE_IDX(seg, ptr) \
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(((uintptr_t)(ptr) - (uintptr_t)(seg)->base) >> SMALL_SEGMENT_V5_PAGE_SHIFT)
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// SMALL_SEGMENT_V5_PAGE_META(seg, ptr) - page_meta への O(1) access(bounds check付き)
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#define SMALL_SEGMENT_V5_PAGE_META(seg, ptr) \
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({ \
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SmallSegmentV5* _seg = (seg); \
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if (__builtin_expect(!_seg, 0)) { \
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(SmallPageMetaV5*)NULL; \
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} else { \
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size_t _idx = SMALL_SEGMENT_V5_PAGE_IDX(_seg, (ptr)); \
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(__builtin_expect(_idx < _seg->num_pages, 1)) ? \
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&_seg->page_meta[_idx] : (SmallPageMetaV5*)NULL; \
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} \
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})
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// SMALL_SEGMENT_V5_VALIDATE_MAGIC(seg) - magic 検証
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#define SMALL_SEGMENT_V5_VALIDATE_MAGIC(seg) \
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(__builtin_expect((seg) && (seg)->magic == SMALL_SEGMENT_V5_MAGIC, 1))
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// SMALL_SEGMENT_V5_VALIDATE_PTR(ptr) - Fail-Fast validation pipeline
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// ptr が valid な v5 segment 内にあるかを検証
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#define SMALL_SEGMENT_V5_VALIDATE_PTR(ptr) \
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({ \
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int _valid = 0; \
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if (__builtin_expect((ptr) != NULL, 1)) { \
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SmallSegmentV5* _seg = SMALL_SEGMENT_V5_BASE_FROM_PTR(ptr); \
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if (SMALL_SEGMENT_V5_VALIDATE_MAGIC(_seg)) { \
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size_t _idx = SMALL_SEGMENT_V5_PAGE_IDX(_seg, (ptr)); \
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_valid = (_idx < _seg->num_pages); \
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} \
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} \
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_valid; \
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})
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// SmallSegmentV5: セグメント構造体
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typedef struct SmallSegmentV5 {
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uintptr_t base; // セグメント先頭アドレス
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uint32_t num_pages; // ページ数(通常は 32)
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uint32_t owner_tid; // オーナースレッド ID
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uint32_t magic; // 0xDEADBEEF for validation
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SmallPageMetaV5 page_meta[SMALL_SEGMENT_V5_NUM_PAGES]; // page metadata array
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} SmallSegmentV5;
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// API(v5-0 では宣言のみ、実装は v5-2)
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SmallSegmentV5* small_segment_v5_acquire(void);
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void small_segment_v5_release(SmallSegmentV5* seg);
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SmallPageMetaV5* small_segment_v5_page_meta_of(void* ptr);
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// Page-level allocation (v5-2 fix for segment reuse)
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SmallPageMetaV5* small_segment_v5_alloc_page(void);
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void small_segment_v5_free_page(SmallPageMetaV5* page);
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#endif // HAKMEM_SMALLSEGMENT_V5_BOX_H
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