Files
hakmem/core/box/hak_alloc_api.inc.h
Moe Charm (CI) 1010a961fb Tiny: fix header/stride mismatch and harden refill paths
- Root cause: header-based class indexing (HEADER_CLASSIDX=1) wrote a 1-byte
  header during allocation, but linear carve/refill and initial slab capacity
  still used bare class block sizes. This mismatch could overrun slab usable
  space and corrupt freelists, causing reproducible SEGV at ~100k iters.

Changes
- Superslab: compute capacity with effective stride (block_size + header for
  classes 0..6; class7 remains headerless) in superslab_init_slab(). Add a
  debug-only bound check in superslab_alloc_from_slab() to fail fast if carve
  would exceed usable bytes.
- Refill (non-P0 and P0): use header-aware stride for all linear carving and
  TLS window bump operations. Ensure alignment/validation in tiny_refill_opt.h
  also uses stride, not raw class size.
- Drain: keep existing defense-in-depth for remote sentinel and sanitize nodes
  before splicing into freelist (already present).

Notes
- This unifies the memory layout across alloc/linear-carve/refill with a single
  stride definition and keeps class7 (1024B) headerless as designed.
- Debug builds add fail-fast checks; release builds remain lean.

Next
- Re-run Tiny benches (256/1024B) in debug to confirm stability, then in
  release. If any remaining crash persists, bisect with HAKMEM_TINY_P0_BATCH_REFILL=0
  to isolate P0 batch carve, and continue reducing branch-miss as planned.
2025-11-09 18:55:50 +09:00

208 lines
7.2 KiB
C

// hak_alloc_api.inc.h — Box: hak_alloc_at() implementation
#ifndef HAK_ALLOC_API_INC_H
#define HAK_ALLOC_API_INC_H
#ifdef HAKMEM_POOL_TLS_PHASE1
#include "../pool_tls.h"
#endif
// Centralized OS mapping boundary to keep syscalls in one place
static inline void* hak_os_map_boundary(size_t size, uintptr_t site_id) {
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t_mmap);
#endif
void* p = hak_alloc_mmap_impl(size);
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_SYSCALL_MMAP, t_mmap);
#endif
(void)site_id; // reserved for future accounting/learning
return p;
}
__attribute__((always_inline))
inline void* hak_alloc_at(size_t size, hak_callsite_t site) {
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t0);
#endif
if (!g_initialized) hak_init();
uintptr_t site_id = (uintptr_t)site;
if (__builtin_expect(size <= TINY_MAX_SIZE, 1)) {
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t_tiny);
#endif
void* tiny_ptr = NULL;
#ifdef HAKMEM_TINY_PHASE6_BOX_REFACTOR
tiny_ptr = hak_tiny_alloc_fast_wrapper(size);
#elif defined(HAKMEM_TINY_PHASE6_ULTRA_SIMPLE)
tiny_ptr = hak_tiny_alloc_ultra_simple(size);
#elif defined(HAKMEM_TINY_PHASE6_METADATA)
tiny_ptr = hak_tiny_alloc_metadata(size);
#else
tiny_ptr = hak_tiny_alloc(size);
#endif
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_TINY_ALLOC, t_tiny);
#endif
if (tiny_ptr) { hkm_ace_track_alloc(); return tiny_ptr; }
// PHASE 7 CRITICAL FIX: No malloc fallback for Tiny failures
// If Tiny fails for size <= TINY_MAX_SIZE, let it flow to Mid/ACE layers
// This prevents mixed HAKMEM/libc allocation bugs
#if HAKMEM_TINY_HEADER_CLASSIDX
if (!tiny_ptr && size <= TINY_MAX_SIZE) {
// Tiny failed - log and continue to Mid/ACE (no early return!)
static int log_count = 0;
if (log_count < 3) {
fprintf(stderr, "[DEBUG] Phase 7: tiny_alloc(%zu) failed, trying Mid/ACE layers (no malloc fallback)\n", size);
log_count++;
}
// Continue to Mid allocation below (do NOT fallback to malloc!)
}
#else
static int log_count = 0; if (log_count < 3) { fprintf(stderr, "[DEBUG] tiny_alloc(%zu) returned NULL, falling back\n", size); log_count++; }
#endif
}
hkm_size_hist_record(size);
#ifdef HAKMEM_POOL_TLS_PHASE1
// Phase 1: Ultra-fast Pool TLS for 8KB-52KB range
if (size >= 8192 && size <= 53248) {
void* pool_ptr = pool_alloc(size);
if (pool_ptr) return pool_ptr;
// Fall through to existing Mid allocator as fallback
}
#endif
if (__builtin_expect(mid_is_in_range(size), 0)) {
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t_mid);
#endif
void* mid_ptr = mid_mt_alloc(size);
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_POOL_GET, t_mid);
#endif
if (mid_ptr) return mid_ptr;
}
#if HAKMEM_FEATURE_EVOLUTION
if (g_evo_sample_mask > 0) {
static _Atomic uint64_t tick_counter = 0;
if ((atomic_fetch_add(&tick_counter, 1) & g_evo_sample_mask) == 0) {
struct timespec now; clock_gettime(CLOCK_MONOTONIC, &now);
uint64_t now_ns = now.tv_sec * 1000000000ULL + now.tv_nsec;
if (hak_evo_tick(now_ns)) {
int new_strategy = hak_elo_select_strategy();
atomic_store(&g_cached_strategy_id, new_strategy);
}
}
}
#endif
size_t threshold;
if (HAK_ENABLED_LEARNING(HAKMEM_FEATURE_ELO)) {
int strategy_id = atomic_load(&g_cached_strategy_id);
threshold = hak_elo_get_threshold(strategy_id);
} else {
threshold = 2097152;
}
if (HAK_ENABLED_CACHE(HAKMEM_FEATURE_BIGCACHE) && size >= threshold) {
void* cached_ptr = NULL;
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t_bc);
#endif
if (hak_bigcache_try_get(size, site_id, &cached_ptr)) {
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_BIGCACHE_GET, t_bc);
#endif
return cached_ptr;
}
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_BIGCACHE_GET, t_bc);
#endif
}
if (size >= 33000 && size <= 34000) {
fprintf(stderr, "[ALLOC] 33KB: TINY_MAX_SIZE=%d, threshold=%zu, condition=%d\n",
TINY_MAX_SIZE, threshold, (size > TINY_MAX_SIZE && size < threshold));
}
if (size > TINY_MAX_SIZE && size < threshold) {
if (size >= 33000 && size <= 34000) {
fprintf(stderr, "[ALLOC] 33KB: Calling hkm_ace_alloc\n");
}
const FrozenPolicy* pol = hkm_policy_get();
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t_ace);
#endif
void* l1 = hkm_ace_alloc(size, site_id, pol);
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_POOL_GET, t_ace);
#endif
if (size >= 33000 && size <= 34000) {
fprintf(stderr, "[ALLOC] 33KB: hkm_ace_alloc returned %p\n", l1);
}
if (l1) return l1;
}
// PHASE 7 CRITICAL FIX: Handle allocation gap (1KB-8KB) when ACE is disabled
// Size range:
// 0-1024: Tiny allocator
// 1025-8191: Gap! (Mid starts at 8KB, ACE often disabled)
// 8KB-32KB: Mid allocator
// 32KB-2MB: ACE (if enabled, otherwise mmap)
// 2MB+: mmap
//
// Solution: Use mmap for gap when ACE failed (ACE disabled or OOM)
// Track final fallback mmaps globally
extern _Atomic uint64_t g_final_fallback_mmap_count;
void* ptr;
if (size >= threshold) {
// Large allocation (>= 2MB default): descend via single boundary
atomic_fetch_add(&g_final_fallback_mmap_count, 1);
ptr = hak_os_map_boundary(size, site_id);
} else if (size >= TINY_MAX_SIZE) {
// Mid-range allocation (1KB-2MB): try mmap as final fallback
// This handles the gap when ACE is disabled or failed
atomic_fetch_add(&g_final_fallback_mmap_count, 1);
static _Atomic int gap_alloc_count = 0;
int count = atomic_fetch_add(&gap_alloc_count, 1);
#if HAKMEM_DEBUG_VERBOSE
if (count < 3) fprintf(stderr, "[HAKMEM] INFO: mid-gap fallback size=%zu\n", size);
#endif
ptr = hak_os_map_boundary(size, site_id);
} else {
// Should never reach here (size <= TINY_MAX_SIZE should be handled by Tiny)
static _Atomic int oom_count = 0;
int count = atomic_fetch_add(&oom_count, 1);
if (count < 10) {
fprintf(stderr, "[HAKMEM] OOM: Unexpected allocation path for size=%zu, returning NULL\n", size);
fprintf(stderr, "[HAKMEM] (OOM count: %d) This should not happen!\n", count + 1);
}
#if HAKMEM_DEBUG_TIMING
HKM_TIME_START(t_malloc);
HKM_TIME_END(HKM_CAT_FALLBACK_MALLOC, t_malloc); // Keep timing for compatibility
#endif
errno = ENOMEM;
return NULL;
}
if (!ptr) return NULL;
if (g_evo_sample_mask > 0) { hak_evo_record_size(size); }
AllocHeader* hdr = (AllocHeader*)((char*)ptr - HEADER_SIZE);
if (hdr->magic != HAKMEM_MAGIC) { fprintf(stderr, "[hakmem] ERROR: Invalid magic in allocated header!\n"); return ptr; }
hdr->alloc_site = site_id;
hdr->class_bytes = (size >= threshold) ? threshold : 0;
#if HAKMEM_DEBUG_TIMING
HKM_TIME_END(HKM_CAT_HAK_ALLOC, t0);
#endif
return ptr;
}
#endif // HAK_ALLOC_API_INC_H