hakmem/core/box/tiny_policy_learner_box.c

// tiny_policy_learner_box.c - Placeholder learner hook

#include "tiny_policy_learner_box.h"
#include "tiny_class_policy_box.h"
#include "tiny_class_stats_box.h"
#include <stdint.h>
#include <stdio.h>

// Simple OBSERVE/LEARN rule (auto profile only):
//   - C7 は常に ON (page + warm, cap=8)
//   - それ以外のクラスから score = shared_lock*4 + uc_miss の上位2つだけ page/warm を ON
//   - warm_cap は C5–C7:8, それ以外:4
//   - スコアが 0 なら何も変更しない
void tiny_policy_learner_tick(void) {
    if (!tiny_class_policy_is_auto()) {
        return;
    }

    TinyClassStatsThread snap = {0};
    tiny_class_stats_snapshot_global(&snap);

    // 事前に全クラスを OFF ベースに初期化（cap はデフォルト値に）
    for (int c = 0; c < TINY_NUM_CLASSES; c++) {
        TinyClassPolicy* p = &g_tiny_class_policy[c];
        p->page_box_enabled = 0;
        p->warm_enabled = 0;
        p->warm_cap = (c >= 5) ? 8 : 4;
        p->tls_carve_enabled = 0;
    }

    // C7 は常に ON
    g_tiny_class_policy[7].page_box_enabled = 1;
    g_tiny_class_policy[7].warm_enabled = 1;
    g_tiny_class_policy[7].warm_cap = 8;
    g_tiny_class_policy[7].tls_carve_enabled = 1;

    // C7 を除く上位2クラスをスコアで選択
    int top1 = -1, top2 = -1;
    uint64_t v1 = 0, v2 = 0;
    for (int i = 0; i < TINY_NUM_CLASSES; i++) {
        if (i == 7) continue;
        uint64_t score = snap.shared_lock[i] * 4 + snap.uc_miss[i];
        if (score > v1) {
            top2 = top1;
            v2 = v1;
            top1 = i;
            v1 = score;
        } else if (score > v2) {
            top2 = i;
            v2 = score;
        }
    }

    // スコアが全く無い場合は C7 だけ維持
    if (v1 == 0) {
        return;
    }

    if (top1 >= 0) {
        TinyClassPolicy* p = &g_tiny_class_policy[top1];
        p->page_box_enabled = 1;
        p->warm_enabled = 1;
        p->tls_carve_enabled = 1;
    }
    if (top2 >= 0 && v2 > 0) {
        TinyClassPolicy* p = &g_tiny_class_policy[top2];
        p->page_box_enabled = 1;
        p->warm_enabled = 1;
        p->tls_carve_enabled = 1;
    }

    // 1-shot ログ（最多 4 回まで）
    static _Atomic uint32_t auto_logs = 0;
    if (tiny_policy_log_enabled()) {
        uint32_t n = atomic_fetch_add_explicit(&auto_logs, 1, memory_order_relaxed);
        if (n < 4) {
            fprintf(stderr, "[POLICY_AUTO_UPDATE] profile=auto (top=%d/%d)\n", top1, top2);
            tiny_class_policy_dump(NULL);
        }
    }
}