## Summary
Implemented Phase 12 Shared SuperSlab Pool (mimalloc-style) to address
SuperSlab allocation churn (877 SuperSlabs → 100-200 target).
## Implementation (ChatGPT + Claude)
1. **Metadata changes** (superslab_types.h):
- Added class_idx to TinySlabMeta (per-slab dynamic class)
- Removed size_class from SuperSlab (no longer per-SuperSlab)
- Changed owner_tid (16-bit) → owner_tid_low (8-bit)
2. **Shared Pool** (hakmem_shared_pool.{h,c}):
- Global pool shared by all size classes
- shared_pool_acquire_slab() - Get free slab for class_idx
- shared_pool_release_slab() - Return slab when empty
- Per-class hints for fast path optimization
3. **Integration** (23 files modified):
- Updated all ss->size_class → meta->class_idx
- Updated all meta->owner_tid → meta->owner_tid_low
- superslab_refill() now uses shared pool
- Free path releases empty slabs back to pool
4. **Build system** (Makefile):
- Added hakmem_shared_pool.o to OBJS_BASE and TINY_BENCH_OBJS_BASE
## Status: ⚠️ Build OK, Runtime CRASH
**Build**: ✅ SUCCESS
- All 23 files compile without errors
- Only warnings: superslab_allocate type mismatch (legacy code)
**Runtime**: ❌ SEGFAULT
- Crash location: sll_refill_small_from_ss()
- Exit code: 139 (SIGSEGV)
- Test case: ./bench_random_mixed_hakmem 1000 256 42
## Known Issues
1. **SEGFAULT in refill path** - Likely shared_pool_acquire_slab() issue
2. **Legacy superslab_allocate()** still exists (type mismatch warning)
3. **Remaining TODOs** from design doc:
- SuperSlab physical layout integration
- slab_handle.h cleanup
- Remove old per-class head implementation
## Next Steps
1. Debug SEGFAULT (gdb backtrace shows sll_refill_small_from_ss)
2. Fix shared_pool_acquire_slab() or superslab_init_slab()
3. Basic functionality test (1K → 100K iterations)
4. Measure SuperSlab count reduction (877 → 100-200)
5. Performance benchmark (+650-860% expected)
## Files Changed (25 files)
core/box/free_local_box.c
core/box/free_remote_box.c
core/box/front_gate_classifier.c
core/hakmem_super_registry.c
core/hakmem_tiny.c
core/hakmem_tiny_bg_spill.c
core/hakmem_tiny_free.inc
core/hakmem_tiny_lifecycle.inc
core/hakmem_tiny_magazine.c
core/hakmem_tiny_query.c
core/hakmem_tiny_refill.inc.h
core/hakmem_tiny_superslab.c
core/hakmem_tiny_superslab.h
core/hakmem_tiny_tls_ops.h
core/slab_handle.h
core/superslab/superslab_inline.h
core/superslab/superslab_types.h
core/tiny_debug.h
core/tiny_free_fast.inc.h
core/tiny_free_magazine.inc.h
core/tiny_remote.c
core/tiny_superslab_alloc.inc.h
core/tiny_superslab_free.inc.h
Makefile
## New Files (3 files)
PHASE12_SHARED_SUPERSLAB_POOL_DESIGN.md
core/hakmem_shared_pool.c
core/hakmem_shared_pool.h
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: ChatGPT <chatgpt@openai.com>
88 lines
2.7 KiB
C
88 lines
2.7 KiB
C
// hakmem_tiny_query.c
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// Phase 2B-1: Query API
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// Extracted from hakmem_tiny.c (lines 4295-4346)
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include "hakmem_tiny.h"
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#include "hakmem_tiny_query_api.h"
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#include "hakmem_tiny_superslab.h"
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#include "hakmem_super_registry.h"
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#include "hakmem_config.h"
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// External globals (defined in hakmem_tiny.c)
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extern int g_tiny_initialized;
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extern int g_use_superslab;
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// g_tiny_class_sizes is in hakmem_tiny.h (static const)
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// External functions
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extern TinySlab* hak_tiny_owner_slab(void* ptr);
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// hak_super_lookup is static inline in hakmem_super_registry.h
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int hak_tiny_is_managed(void* ptr) {
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if (!ptr || !g_tiny_initialized) return 0;
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// Phase 6.12.1: O(1) slab lookup via registry/list
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return hak_tiny_owner_slab(ptr) != NULL || hak_super_lookup(ptr) != NULL;
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}
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int hak_tiny_is_managed_superslab(void* ptr) {
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if (!ptr || !g_tiny_initialized) return 0;
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// Safety: Only check if g_use_superslab is enabled
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if (g_use_superslab) {
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SuperSlab* ss = hak_super_lookup(ptr);
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if (ss && ss->magic == SUPERSLAB_MAGIC) {
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// Phase 12: Use registry hit as "managed by SuperSlab"
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return 1;
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}
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}
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// Fallback to TinySlab check
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return hak_tiny_owner_slab(ptr) != NULL;
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}
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size_t hak_tiny_usable_size(void* ptr) {
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if (!ptr || !g_tiny_initialized) return 0;
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// Check SuperSlab first via registry (safe under direct link and LD)
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if (g_use_superslab) {
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SuperSlab* ss = hak_super_lookup(ptr);
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if (ss && ss->magic == SUPERSLAB_MAGIC) {
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// Phase 12: derive class from per-slab meta (no ss->size_class)
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void* base = (void*)((uint8_t*)ptr - 1);
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int slab_idx = slab_index_for(ss, base);
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if (slab_idx >= 0 && slab_idx < ss_slabs_capacity(ss)) {
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TinySlabMeta* meta = &ss->slabs[slab_idx];
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int k = (meta->class_idx < TINY_NUM_CLASSES) ? (int)meta->class_idx : -1;
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if (k >= 0) {
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#if HAKMEM_TINY_HEADER_CLASSIDX
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size_t stride = g_tiny_class_sizes[k];
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return (stride > 0) ? (stride - 1) : 0;
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#else
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return g_tiny_class_sizes[k];
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#endif
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}
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}
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}
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}
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// Fallback: TinySlab owner lookup
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TinySlab* slab = hak_tiny_owner_slab(ptr);
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if (slab) {
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int k = slab->class_idx;
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if (k >= 0 && k < TINY_NUM_CLASSES) {
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// Phase E1-CORRECT: g_tiny_class_sizes = total size (stride)
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// Usable = stride - 1 (for 1-byte header)
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#if HAKMEM_TINY_HEADER_CLASSIDX
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size_t stride = g_tiny_class_sizes[k];
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return (stride > 0) ? (stride - 1) : 0;
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#else
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return g_tiny_class_sizes[k];
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#endif
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}
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}
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return 0;
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}
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