Files
hakmem/core/hakmem_tiny_tls_ops.h
Moe Charm (CI) c9053a43ac Phase 6-2.3~6-2.5: Critical bug fixes + SuperSlab optimization (WIP)
## Phase 6-2.3: Fix 4T Larson crash (active counter bug) 
**Problem:** 4T Larson crashed with "free(): invalid pointer", OOM errors
**Root cause:** core/hakmem_tiny_refill_p0.inc.h:103
  - P0 batch refill moved freelist blocks to TLS cache
  - Active counter NOT incremented → double-decrement on free
  - Counter underflows → SuperSlab appears full → OOM → crash
**Fix:** Added ss_active_add(tls->ss, from_freelist);
**Result:** 4T stable at 838K ops/s 

## Phase 6-2.4: Fix SEGV in random_mixed/mid_large_mt benchmarks 
**Problem:** bench_random_mixed_hakmem, bench_mid_large_mt_hakmem → immediate SEGV
**Root cause #1:** core/box/hak_free_api.inc.h:92-95
  - "Guess loop" dereferenced unmapped memory when registry lookup failed
**Root cause #2:** core/box/hak_free_api.inc.h:115
  - Header magic check dereferenced unmapped memory
**Fix:**
  1. Removed dangerous guess loop (lines 92-95)
  2. Added hak_is_memory_readable() check before dereferencing header
     (core/hakmem_internal.h:277-294 - uses mincore() syscall)
**Result:**
  - random_mixed (2KB): SEGV → 2.22M ops/s 
  - random_mixed (4KB): SEGV → 2.58M ops/s 
  - Larson 4T: no regression (838K ops/s) 

## Phase 6-2.5: Performance investigation + SuperSlab fix (WIP) ⚠️
**Problem:** Severe performance gaps (19-26x slower than system malloc)
**Investigation:** Task agent identified root cause
  - hak_is_memory_readable() syscall overhead (100-300 cycles per free)
  - ALL frees hit unmapped_header_fallback path
  - SuperSlab lookup NEVER called
  - Why? g_use_superslab = 0 (disabled by diet mode)

**Root cause:** core/hakmem_tiny_init.inc:104-105
  - Diet mode (default ON) disables SuperSlab
  - SuperSlab defaults to 1 (hakmem_config.c:334)
  - BUT diet mode overrides it to 0 during init

**Fix:** Separate SuperSlab from diet mode
  - SuperSlab: Performance-critical (fast alloc/free)
  - Diet mode: Memory efficiency (magazine capacity limits only)
  - Both are independent features, should not interfere

**Status:** ⚠️ INCOMPLETE - New SEGV discovered after fix
  - SuperSlab lookup now works (confirmed via debug output)
  - But benchmark crashes (Exit 139) after ~20 lookups
  - Needs further investigation

**Files modified:**
- core/hakmem_tiny_init.inc:99-109 - Removed diet mode override
- PERFORMANCE_INVESTIGATION_REPORT.md - Task agent analysis (303x instruction gap)

**Next steps:**
- Investigate new SEGV (likely SuperSlab free path bug)
- OR: Revert Phase 6-2.5 changes if blocking progress

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-07 20:31:01 +09:00

267 lines
9.6 KiB
C

#ifndef HAKMEM_TINY_TLS_OPS_H
#define HAKMEM_TINY_TLS_OPS_H
#include "hakmem_tiny.h"
#include "hakmem_tiny_superslab.h"
#include "hakmem_super_registry.h"
#include "tiny_remote.h"
#include <stdint.h>
// Forward declarations for external dependencies
extern int g_use_superslab;
extern const size_t g_tiny_class_sizes[TINY_NUM_CLASSES];
extern __thread TinyTLSSlab g_tls_slabs[TINY_NUM_CLASSES];
extern __thread void* g_tls_sll_head[TINY_NUM_CLASSES];
extern __thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES];
extern __thread void* g_fast_head[TINY_NUM_CLASSES];
extern __thread uint16_t g_fast_count[TINY_NUM_CLASSES];
extern __thread TinyTLSList g_tls_lists[TINY_NUM_CLASSES];
extern __thread TinySlab* g_tls_active_slab_a[TINY_NUM_CLASSES];
extern __thread TinySlab* g_tls_active_slab_b[TINY_NUM_CLASSES];
extern PaddedLock g_tiny_class_locks[TINY_NUM_CLASSES];
#if !HAKMEM_BUILD_RELEASE
extern __thread TinyTLSMag g_tls_mags[TINY_NUM_CLASSES];
void tiny_small_mags_init_once(void);
void tiny_mag_init_if_needed(int class_idx);
#endif
#if HAKMEM_BUILD_DEBUG
extern uint64_t g_tls_spill_ss_count[TINY_NUM_CLASSES];
extern uint64_t g_tls_spill_owner_count[TINY_NUM_CLASSES];
extern uint64_t g_tls_spill_mag_count[TINY_NUM_CLASSES];
extern uint64_t g_tls_spill_requeue_count[TINY_NUM_CLASSES];
#endif
// NOTE: Helper functions are defined in hakmem_tiny.c before this header is included
// No forward declarations needed - functions are already visible
// ============================================================================
// TLS Operations - Hot Path Functions (Inline for Performance)
// ============================================================================
// Refill TLS list from TLS-bound SuperSlab (100-line hot path)
static inline int tls_refill_from_tls_slab(int class_idx, TinyTLSList* tls, uint32_t want) {
if (!g_use_superslab || tls == NULL) return 0;
TinyTLSSlab* tls_slab = &g_tls_slabs[class_idx];
if (!tls_slab->ss) {
if (superslab_refill(class_idx) == NULL) return 0;
}
TinySlabMeta* meta = tls_slab->meta;
if (!meta) return 0;
uint32_t cap = tls_list_spill_threshold(tls);
if (tls->count >= cap) return 0;
uint32_t room = cap - tls->count;
if (want == 0u || want > room) want = room;
if (want == 0u) return 0;
size_t block_size = g_tiny_class_sizes[class_idx];
void* accum_head = NULL;
void* accum_tail = NULL;
uint32_t total = 0u;
uint8_t* slab_base = tls_slab->slab_base ? tls_slab->slab_base
: (tls_slab->ss ? tiny_slab_base_for(tls_slab->ss, tls_slab->slab_idx) : NULL);
while (total < want) {
// 1) 再利用フリーリスト
if (meta->freelist) {
void* local_head = NULL;
void* local_tail = NULL;
uint32_t local = 0u;
uint32_t need = want - total;
while (local < need && meta->freelist) {
void* node = meta->freelist;
meta->freelist = *(void**)node;
*(void**)node = local_head;
local_head = node;
if (!local_tail) local_tail = node;
local++;
}
if (local > 0u) {
// Do not adjust active here (blocks not yet returned to user)
meta->used += local;
if (!accum_head) {
accum_head = local_head;
accum_tail = local_tail;
} else {
*(void**)local_tail = accum_head;
accum_head = local_head;
}
total += local;
continue;
}
}
// 2) Superslab の線形領域からまとめて切り出す
if (meta->used >= meta->capacity) {
if (superslab_refill(class_idx) == NULL) break;
meta = tls_slab->meta;
if (!meta) break;
block_size = g_tiny_class_sizes[class_idx];
slab_base = tls_slab->slab_base ? tls_slab->slab_base
: (tls_slab->ss ? tiny_slab_base_for(tls_slab->ss, tls_slab->slab_idx) : NULL);
continue;
}
uint32_t need = want - total;
uint32_t available = meta->capacity - meta->used;
if (available == 0u) continue;
if (need > available) need = available;
if (!slab_base) {
slab_base = tiny_slab_base_for(tls_slab->ss, tls_slab->slab_idx);
}
uint8_t* base_cursor = slab_base + ((size_t)meta->used * block_size);
void* local_head = (void*)base_cursor;
uint8_t* cursor = base_cursor;
for (uint32_t i = 1; i < need; ++i) {
uint8_t* next = cursor + block_size;
*(void**)cursor = (void*)next;
cursor = next;
}
void* local_tail = (void*)cursor;
meta->used += need;
// Do not adjust active here (blocks not yet returned to user)
if (!accum_head) {
accum_head = local_head;
accum_tail = local_tail;
} else {
*(void**)local_tail = accum_head;
accum_head = local_head;
}
total += need;
}
if (total > 0u && accum_head) {
tls_list_bulk_put(tls, accum_head, accum_tail, total);
return (int)total;
}
return 0;
}
// Spill excess TLS list back to owners (96-line hot path)
static inline void tls_list_spill_excess(int class_idx, TinyTLSList* tls) {
uint32_t cap = tls_list_spill_threshold(tls);
if (tls->count <= cap) return;
uint32_t excess = tls->count - cap;
void* head = NULL;
void* tail = NULL;
uint32_t taken = tls_list_bulk_take(tls, excess, &head, &tail);
if (taken == 0u || head == NULL) return;
#if HAKMEM_PROF_STATIC && HAKMEM_BUILD_DEBUG
struct timespec ts_tls;
int prof_sample = hkm_prof_begin(&ts_tls);
#endif
#if !HAKMEM_BUILD_RELEASE
tiny_small_mags_init_once();
if (class_idx > 3) tiny_mag_init_if_needed(class_idx);
TinyTLSMag* mag = &g_tls_mags[class_idx];
#else
TinyTLSMag* mag = NULL;
(void)mag;
#endif
void* requeue_head = NULL;
void* requeue_tail = NULL;
uint32_t requeue_count = 0;
uint32_t self_tid = tiny_self_u32();
void* node = head;
while (node) {
void* next = *(void**)node;
int handled = 0;
// Phase 1: Try SuperSlab first (registry-based lookup, no false positives)
SuperSlab* ss = hak_super_lookup(node);
if (ss && ss->magic == SUPERSLAB_MAGIC) {
int slab_idx = slab_index_for(ss, node);
TinySlabMeta* meta = &ss->slabs[slab_idx];
if (!tiny_remote_guard_allow_local_push(ss, slab_idx, meta, node, "tls_spill_ss", self_tid)) {
(void)ss_remote_push(ss, slab_idx, node);
if (meta->used > 0) meta->used--;
handled = 1;
} else {
void* prev = meta->freelist;
*(void**)node = prev;
meta->freelist = node;
tiny_failfast_log("tls_spill_ss", ss->size_class, ss, meta, node, prev);
if (meta->used > 0) meta->used--;
// Active was decremented at free time
handled = 1;
}
#if HAKMEM_BUILD_DEBUG
g_tls_spill_ss_count[class_idx]++;
#endif
tiny_obs_record(3, class_idx); // TINY_OBS_SPILL_SS
}
if (!handled) {
TinySlab* owner = tls_active_owner_for_ptr(class_idx, node);
if (owner && !mini_mag_is_full(&owner->mini_mag)) {
mini_mag_push(&owner->mini_mag, node);
handled = 1;
#if HAKMEM_BUILD_DEBUG
g_tls_spill_owner_count[class_idx]++;
#endif
tiny_obs_record(4, class_idx); // TINY_OBS_SPILL_OWNER
}
}
#if !HAKMEM_BUILD_RELEASE
if (!handled) {
if (mag && mag->cap > 0 && mag->top < mag->cap) {
mag->items[mag->top].ptr = node;
#if HAKMEM_TINY_MAG_OWNER
TinySlab* owner_hint = tls_active_owner_for_ptr(class_idx, node);
mag->items[mag->top].owner = owner_hint;
#endif
mag->top++;
if (__builtin_expect(tiny_remote_watch_is(node), 0)) {
SuperSlab* watch_ss = hak_super_lookup(node);
int watch_idx = (watch_ss && watch_ss->magic == SUPERSLAB_MAGIC) ? slab_index_for(watch_ss, node) : -1;
tiny_remote_watch_note("mag_push", watch_ss, watch_idx, node, 0xA242u, 0, 0);
}
handled = 1;
#if HAKMEM_BUILD_DEBUG
g_tls_spill_mag_count[class_idx]++;
#endif
tiny_obs_record(5, class_idx); // TINY_OBS_SPILL_MAG
}
}
#endif
if (!handled) {
*(void**)node = requeue_head;
if (!requeue_head) requeue_tail = node;
requeue_head = node;
requeue_count++;
#if HAKMEM_BUILD_DEBUG
g_tls_spill_requeue_count[class_idx]++;
#endif
tiny_obs_record(6, class_idx); // TINY_OBS_SPILL_REQUEUE
}
node = next;
}
if (requeue_head) {
tls_list_bulk_put(tls, requeue_head, requeue_tail, requeue_count);
}
#if HAKMEM_PROF_STATIC && HAKMEM_BUILD_DEBUG
hkm_prof_end(prof_sample, HKP_TINY_TLS_SPILL, &ts_tls);
#endif
}
// ============================================================================
// TLS Operations - Cold Path Functions (Implemented in .c)
// ============================================================================
// Drain all TLS caches back to global pool (cold path, 89 lines)
void tiny_tls_cache_drain(int class_idx);
#endif // HAKMEM_TINY_TLS_OPS_H