Phase 36-37: TinyHotHeap v2 HotBox redesign and C7 current_page policy fixes

- Redefine TinyHotHeap v2 as per-thread Hot Box with clear boundaries
- Add comprehensive OS statistics tracking for SS allocations
- Implement route-based free handling for TinyHeap v2
- Add C6/C7 debugging and statistics improvements
- Update documentation with implementation guidelines and analysis
- Add new box headers for stats, routing, and front-end management

core/superslab_cache.c

@@ -4,6 +4,7 @@
 // Date: 2025-11-28
 
 #include "hakmem_tiny_superslab_internal.h"
+#include "box/ss_os_acquire_box.h"
 
 // ============================================================================
 // Cache System - Global Variables
@@ -60,10 +61,12 @@ void* ss_os_acquire(uint8_t size_class, size_t ss_size, uintptr_t ss_mask, int p
                -1, 0);
     if (ptr != MAP_FAILED) {
         atomic_fetch_add(&g_ss_mmap_count, 1);
+        ss_os_stats_record_alloc();
         if (((uintptr_t)ptr & ss_mask) == 0) {
             ss_stats_os_alloc(size_class, ss_size);
             return ptr;
         }
+        ss_os_stats_record_free();
         munmap(ptr, ss_size);
         ptr = NULL;
     } else {
@@ -79,6 +82,7 @@ void* ss_os_acquire(uint8_t size_class, size_t ss_size, uintptr_t ss_mask, int p
                      -1, 0);
     if (raw != MAP_FAILED) {
         uint64_t count = atomic_fetch_add(&g_ss_mmap_count, 1) + 1;
+        ss_os_stats_record_alloc();
         #if !HAKMEM_BUILD_RELEASE
         if (log_count < 10) {
             fprintf(stderr, "[SUPERSLAB_MMAP] #%lu: class=%d size=%zu (total SuperSlab mmaps so far)\n",
@@ -98,11 +102,13 @@ void* ss_os_acquire(uint8_t size_class, size_t ss_size, uintptr_t ss_mask, int p
 
     size_t prefix_size = aligned_addr - raw_addr;
     if (prefix_size > 0) {
+        ss_os_stats_record_free();
         munmap(raw, prefix_size);
     }
     size_t suffix_size = alloc_size - prefix_size - ss_size;
     if (suffix_size > 0) {
         // 余剰領域は常に munmap して、実際に使用する SuperSlab サイズだけを残す。
+        ss_os_stats_record_free();
         munmap((char*)ptr + ss_size, suffix_size);
     }
 
@@ -111,6 +117,7 @@ void* ss_os_acquire(uint8_t size_class, size_t ss_size, uintptr_t ss_mask, int p
     // CRITICAL FIX (2025-12-05): Use MADV_POPULATE_WRITE for efficiency
 #ifdef MADV_POPULATE_WRITE
     int ret = madvise(ptr, ss_size, MADV_POPULATE_WRITE);
+    ss_os_stats_record_madvise();
     if (ret != 0) {
         // Fallback: explicit memset
         memset(ptr, 0, ss_size);
@@ -118,6 +125,7 @@ void* ss_os_acquire(uint8_t size_class, size_t ss_size, uintptr_t ss_mask, int p
 #else
     // Fallback for kernels < 5.14
     memset(ptr, 0, ss_size);
+    ss_os_stats_record_madvise();
 #endif
 
     ss_stats_os_alloc(size_class, ss_size);