03df05ec75
## 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>
25 lines
1.1 KiB
C
25 lines
1.1 KiB
C
#include "free_remote_box.h"
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#include "free_publish_box.h"
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#include "hakmem_tiny.h"
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int tiny_free_remote_box(SuperSlab* ss, int slab_idx, TinySlabMeta* meta, void* ptr, uint32_t my_tid) {
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extern _Atomic uint64_t g_free_remote_box_calls;
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atomic_fetch_add_explicit(&g_free_remote_box_calls, 1, memory_order_relaxed);
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if (!(ss && ss->magic == SUPERSLAB_MAGIC)) return 0;
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if (slab_idx < 0 || slab_idx >= ss_slabs_capacity(ss)) return 0;
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(void)my_tid;
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// BUGFIX: Decrement used BEFORE remote push to maintain visibility consistency
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// Remote push uses memory_order_release, so drainer must see updated used count
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meta->used--;
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int transitioned = ss_remote_push(ss, slab_idx, ptr); // ss_active_dec_one() called inside
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// ss_active_dec_one(ss); // REMOVED: Already called inside ss_remote_push()
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if (transitioned) {
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// Phase 12: use per-slab class for publish metadata
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uint8_t cls = (meta && meta->class_idx < TINY_NUM_CLASSES) ? meta->class_idx : 0;
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tiny_free_publish_remote_transition((int)cls, ss, slab_idx);
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return 1;
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}
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return 0;
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}
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