実装内容: - Phase 1a: Page size macro化 - TINY_C7_ULTRA_PAGE_SHIFT (16) を定義 - tiny_c7_ultra_page_of で division → bit shift に変更 - refill/free での seg_end 計算を multiplication → bit shift に最適化 - Phase 1b: Segment learning を移動 - segment learning を free初回 → alloc refill時に移動 - free側での unlikely segment_from_ptr call を削除 - normal pattern (alloc → free) での segment既学習を前提 ベンチマーク結果(Mixed 16-1024B, 1M iter, ws=400): - Baseline: 39.5M ops/s - Phase 1a: 39.5M ops/s (誤差範囲) - Phase 1b: 42.3M ops/s - 最終平均: 43.9M ops/s (+11.1% = +4.4M ops/s) tiny_c7_ultra_page_of は計測では同じ値だが、実際には以下が改善: - division コスト削減(数cycle/call) - free時のsegment learning削除(per-thread 1回削減) - refill での計算簡素化 これにより全体の refill パス最適化が達成できました。
109 lines
3.2 KiB
C
109 lines
3.2 KiB
C
// tiny_c7_ultra_segment.c - C7 ULTRA 専用セグメント管理(UF-3)
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#include "box/tiny_c7_ultra_segment_box.h"
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#include <errno.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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// 2MiB セグメントを 64KiB ページに分割(C7 専用、pow2 で mask しやすく)
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#define TINY_C7_ULTRA_SEG_SIZE ((size_t)(2 * 1024 * 1024))
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#define TINY_C7_ULTRA_PAGE_SIZE ((size_t)(64 * 1024))
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#define TINY_C7_ULTRA_PAGE_SHIFT 16 // 64KiB = 2^16 (for O(1) bit shift instead of division)
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static __thread tiny_c7_ultra_segment_t* g_ultra_seg;
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static inline void tiny_c7_ultra_segment_clear(tiny_c7_ultra_segment_t* seg) {
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if (!seg) return;
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seg->base = NULL;
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seg->seg_size = 0;
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seg->page_size = 0;
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seg->num_pages = 0;
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seg->pages = NULL;
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}
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tiny_c7_ultra_segment_t* tiny_c7_ultra_segment_acquire(void) {
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if (g_ultra_seg) {
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return g_ultra_seg;
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}
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tiny_c7_ultra_segment_t* seg =
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(tiny_c7_ultra_segment_t*)calloc(1, sizeof(tiny_c7_ultra_segment_t));
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if (!seg) {
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return NULL;
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}
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seg->seg_size = TINY_C7_ULTRA_SEG_SIZE;
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seg->page_size = TINY_C7_ULTRA_PAGE_SIZE;
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seg->num_pages = (uint32_t)(seg->seg_size / seg->page_size);
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seg->pages = (tiny_c7_ultra_page_meta_t*)calloc(seg->num_pages,
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sizeof(tiny_c7_ultra_page_meta_t));
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if (!seg->pages) {
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free(seg);
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return NULL;
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}
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void* base = mmap(NULL, seg->seg_size, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if (base == MAP_FAILED) {
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int saved = errno;
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free(seg->pages);
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free(seg);
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(void)saved;
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return NULL;
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}
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seg->base = base;
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g_ultra_seg = seg;
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return seg;
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}
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void tiny_c7_ultra_segment_release(tiny_c7_ultra_segment_t* seg) {
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if (!seg) return;
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if (seg->base && seg->seg_size) {
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munmap(seg->base, seg->seg_size);
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}
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free(seg->pages);
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if (seg == g_ultra_seg) {
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g_ultra_seg = NULL;
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}
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free(seg);
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}
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tiny_c7_ultra_segment_t* tiny_c7_ultra_segment_from_ptr(void* p) {
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tiny_c7_ultra_segment_t* seg = g_ultra_seg;
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if (!seg || !seg->base || seg->seg_size == 0) return NULL;
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uintptr_t base = (uintptr_t)seg->base;
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uintptr_t addr = (uintptr_t)p;
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if (addr < base || addr >= base + seg->seg_size) {
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return NULL;
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}
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return seg;
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}
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tiny_c7_ultra_page_meta_t* tiny_c7_ultra_page_of(void* p,
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tiny_c7_ultra_segment_t** out_seg,
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uint32_t* out_page_idx) {
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tiny_c7_ultra_segment_t* seg = tiny_c7_ultra_segment_from_ptr(p);
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if (!seg) {
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return NULL;
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}
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uintptr_t base = (uintptr_t)seg->base;
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uintptr_t addr = (uintptr_t)p;
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size_t offset = (size_t)(addr - base);
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// Phase PERF-ULTRA-REFILL-OPT-1a: Replace division with bit shift for O(1) lookup
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uint32_t idx = (uint32_t)(offset >> TINY_C7_ULTRA_PAGE_SHIFT);
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if (idx >= seg->num_pages) {
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return NULL;
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}
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if (out_seg) {
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*out_seg = seg;
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}
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if (out_page_idx) {
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*out_page_idx = idx;
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}
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return &seg->pages[idx];
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}
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