984cca41ef
Performance Results: - Throughput: 2.66M ops/s → 3.8M ops/s (+43% improvement) - sp_meta_find_or_create: O(N) linear scan → O(1) direct pointer - Stage 2 metadata scan: 100% → 10-20% (80-90% reduction via hints) Core Optimizations: 1. O(1) Metadata Lookup (superslab_types.h) - Added `shared_meta` pointer field to SuperSlab struct - Eliminates O(N) linear search through ss_metadata[] array - First access: O(N) scan + cache | Subsequent: O(1) direct return 2. sp_meta_find_or_create Fast Path (hakmem_shared_pool.c) - Check cached ss->shared_meta first before linear scan - Cache pointer after successful linear scan for future lookups - Reduces 7.8% CPU hotspot to near-zero for hot paths 3. Stage 2 Class Hints Fast Path (hakmem_shared_pool_acquire.c) - Try class_hints[class_idx] FIRST before full metadata scan - Uses O(1) ss->shared_meta lookup for hint validation - __builtin_expect() for branch prediction optimization - 80-90% of acquire calls now skip full metadata scan 4. Proper Initialization (ss_allocation_box.c) - Initialize shared_meta = NULL in superslab_allocate() - Ensures correct NULL-check semantics for new SuperSlabs Additional Improvements: - Updated ptr_trace and debug ring for release build efficiency - Enhanced ENV variable documentation and analysis - Added learner_env_box.h for configuration management - Various Box optimizations for reduced overhead Thread Safety: - All atomic operations use correct memory ordering - shared_meta cached under mutex protection - Lock-free Stage 2 uses proper CAS with acquire/release semantics Testing: - Benchmark: 1M iterations, 3.8M ops/s stable - Build: Clean compile RELEASE=0 and RELEASE=1 - No crashes, memory leaks, or correctness issues Next Optimization Candidates: - P1: Per-SuperSlab free slot bitmap for O(1) slot claiming - P2: Reduce Stage 2 critical section size - P3: Page pre-faulting (MAP_POPULATE) 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
#ifndef TINY_DEBUG_RING_H
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#define TINY_DEBUG_RING_H
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#include <stdint.h>
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#include <stddef.h>
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#include "hakmem_build_flags.h"
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// Tiny Debug Ring Trace (Phase 8 tooling)
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// Trace control:
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// - HAKMEM_TINY_TRACE_RING=1
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// - or HAKMEM_TRACE=ring
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// Records recent alloc/free events and dumps them on SIGSEGV.
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enum {
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TINY_RING_EVENT_ALLOC_ENTER = 1,
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TINY_RING_EVENT_ALLOC_SUCCESS,
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TINY_RING_EVENT_ALLOC_NULL,
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TINY_RING_EVENT_ALLOC_REFILL_START,
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TINY_RING_EVENT_ALLOC_REFILL_NULL,
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TINY_RING_EVENT_ALLOC_BIND,
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TINY_RING_EVENT_FREE_ENTER,
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TINY_RING_EVENT_FREE_FAST,
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TINY_RING_EVENT_FREE_REMOTE,
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TINY_RING_EVENT_FREE_LOCAL,
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TINY_RING_EVENT_FREE_RETURN_MAG,
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TINY_RING_EVENT_SUPERSLAB_ADOPT,
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TINY_RING_EVENT_SUPERSLAB_ALLOC,
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TINY_RING_EVENT_SUPERSLAB_PUBLISH,
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TINY_RING_EVENT_SUPERSLAB_ADOPT_FAIL,
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TINY_RING_EVENT_REMOTE_PUSH,
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TINY_RING_EVENT_REMOTE_INVALID,
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TINY_RING_EVENT_REMOTE_DRAIN,
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TINY_RING_EVENT_OWNER_ACQUIRE,
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TINY_RING_EVENT_OWNER_RELEASE,
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TINY_RING_EVENT_FRONT_BYPASS,
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TINY_RING_EVENT_MAILBOX_PUBLISH,
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TINY_RING_EVENT_MAILBOX_FETCH,
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TINY_RING_EVENT_MAILBOX_FETCH_NULL,
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TINY_RING_EVENT_ROUTE,
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// TLS SLL anomalies (investigation aid, gated by HAKMEM_TINY_SLL_RING)
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TINY_RING_EVENT_TLS_SLL_REJECT = 0x7F10,
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TINY_RING_EVENT_TLS_SLL_SENTINEL = 0x7F11,
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TINY_RING_EVENT_TLS_SLL_HDR_CORRUPT = 0x7F12
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};
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// Function declarations (implementation in tiny_debug_ring.c)
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void tiny_debug_ring_init(void);
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void tiny_debug_ring_record(uint16_t event, uint16_t class_idx, void* ptr, uintptr_t aux);
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#endif // TINY_DEBUG_RING_H
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