1010a961fb
- 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.
760 lines
34 KiB
C
760 lines
34 KiB
C
// tiny_superslab_alloc.inc.h - SuperSlab Allocation Layer
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// Purpose: Slab allocation, refill, and adoption logic
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// Extracted from: hakmem_tiny_free.inc lines 626-1170
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// Box Theory: Box 4 (Refill/Adoption) integration
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//
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// Public functions:
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// - superslab_alloc_from_slab(): Allocate from specific slab (linear or freelist)
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// - superslab_refill(): Refill TLS slab (adoption, registry scan, fresh alloc)
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// - hak_tiny_alloc_superslab(): Main SuperSlab allocation entry point
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// ============================================================================
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// Phase 6.23: SuperSlab Allocation Helpers
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// ============================================================================
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// Phase 6.24: Allocate from SuperSlab slab (lazy freelist + linear allocation)
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#include "hakmem_tiny_superslab_constants.h"
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static inline void* superslab_alloc_from_slab(SuperSlab* ss, int slab_idx) {
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TinySlabMeta* meta = &ss->slabs[slab_idx];
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// Ensure remote queue is drained before handing blocks back to TLS (UNLIKELY in 1T)
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if (__builtin_expect(atomic_load_explicit(&ss->remote_heads[slab_idx], memory_order_acquire) != 0, 0)) {
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uint32_t self_tid = tiny_self_u32();
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SlabHandle h = slab_try_acquire(ss, slab_idx, self_tid);
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if (slab_is_valid(&h)) {
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slab_drain_remote_full(&h);
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int pending = atomic_load_explicit(&ss->remote_heads[slab_idx], memory_order_acquire) != 0;
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if (__builtin_expect(pending, 0)) {
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if (__builtin_expect(g_debug_remote_guard, 0)) {
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uintptr_t head = atomic_load_explicit(&ss->remote_heads[slab_idx], memory_order_relaxed);
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tiny_remote_watch_note("alloc_pending_remote",
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ss,
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slab_idx,
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(void*)head,
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0xA243u,
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self_tid,
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0);
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}
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slab_release(&h);
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return NULL;
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}
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slab_release(&h);
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} else {
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if (__builtin_expect(g_debug_remote_guard, 0)) {
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tiny_remote_watch_note("alloc_acquire_fail",
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ss,
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slab_idx,
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meta,
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0xA244u,
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self_tid,
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0);
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}
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return NULL;
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}
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}
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if (__builtin_expect(g_debug_remote_guard, 0)) {
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uintptr_t head_pending = atomic_load_explicit(&ss->remote_heads[slab_idx], memory_order_acquire);
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if (head_pending != 0) {
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tiny_remote_watch_note("alloc_remote_pending",
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ss,
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slab_idx,
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(void*)head_pending,
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0xA247u,
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tiny_self_u32(),
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1);
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return NULL;
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}
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}
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// Phase 6.24: Linear allocation mode (freelist == NULL)
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// This avoids the 4000-8000 cycle cost of building freelist on init
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if (__builtin_expect(meta->freelist == NULL && meta->used < meta->capacity, 1)) {
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// Linear allocation: use canonical tiny_slab_base_for() only
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size_t unit_sz = g_tiny_class_sizes[ss->size_class]
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#if HAKMEM_TINY_HEADER_CLASSIDX
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+ ((ss->size_class != 7) ? 1 : 0)
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#endif
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;
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uint8_t* base = tiny_slab_base_for(ss, slab_idx);
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void* block_base = (void*)(base + ((size_t)meta->used * unit_sz));
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#if !HAKMEM_BUILD_RELEASE
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// Debug safety: Ensure we never carve past slab usable region (capacity mismatch guard)
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size_t dbg_usable = (slab_idx == 0) ? SUPERSLAB_SLAB0_USABLE_SIZE : SUPERSLAB_SLAB_USABLE_SIZE;
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uintptr_t dbg_off = (uintptr_t)((uint8_t*)block_base - base);
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if (__builtin_expect(dbg_off + unit_sz > dbg_usable, 0)) {
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fprintf(stderr, "[TINY_ALLOC_BOUNDS] cls=%u slab=%d used=%u cap=%u unit=%zu off=%lu usable=%zu\n",
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ss->size_class, slab_idx, meta->used, meta->capacity, unit_sz,
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(unsigned long)dbg_off, dbg_usable);
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return NULL;
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}
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#endif
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meta->used++;
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void* user =
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#if HAKMEM_TINY_HEADER_CLASSIDX
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tiny_region_id_write_header(block_base, ss->size_class);
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#else
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block_base;
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#endif
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if (__builtin_expect(g_debug_remote_guard, 0)) {
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tiny_remote_track_on_alloc(ss, slab_idx, user, "linear_alloc", 0);
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tiny_remote_assert_not_remote(ss, slab_idx, user, "linear_alloc_ret", 0);
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}
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return user; // Fast path: O(1) pointer arithmetic
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}
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// Freelist mode (after first free())
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if (__builtin_expect(meta->freelist != NULL, 0)) {
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void* block = meta->freelist;
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// CORRUPTION DEBUG: Validate freelist head before popping
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if (__builtin_expect(tiny_refill_failfast_level() >= 2, 0)) {
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size_t blk = g_tiny_class_sizes[ss->size_class];
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uint8_t* slab_base = tiny_slab_base_for(ss, slab_idx);
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uintptr_t block_addr = (uintptr_t)block;
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uintptr_t slab_addr = (uintptr_t)slab_base;
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uintptr_t offset = block_addr - slab_addr;
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fprintf(stderr, "[ALLOC_POP] cls=%u slab=%d block=%p offset=%zu (used=%u cap=%u)\n",
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ss->size_class, slab_idx, block, offset, meta->used, meta->capacity);
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if (offset % blk != 0) {
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fprintf(stderr, "[ALLOC_CORRUPT] Freelist head is misaligned! block=%p offset=%zu blk=%zu\n",
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block, offset, blk);
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fprintf(stderr, "[ALLOC_CORRUPT] Expected alignment: %zu, actual: %zu\n",
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blk, offset % blk);
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tiny_failfast_abort_ptr("alloc_pop_misalign", ss, slab_idx, block, "freelist_head_corrupt");
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}
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size_t index = offset / blk;
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if (index >= meta->capacity) {
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fprintf(stderr, "[ALLOC_CORRUPT] Freelist head out of bounds! block=%p index=%zu cap=%u\n",
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block, index, meta->capacity);
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tiny_failfast_abort_ptr("alloc_pop_oob", ss, slab_idx, block, "freelist_head_oob");
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}
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}
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meta->freelist = *(void**)block; // Pop from freelist
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meta->used++;
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if (__builtin_expect(tiny_refill_failfast_level() >= 2, 0)) {
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if (__builtin_expect(meta->used > meta->capacity, 0)) {
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fprintf(stderr, "[ALLOC_CORRUPT] meta->used overflow on freelist alloc: used=%u cap=%u cls=%u slab=%d\n",
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meta->used, meta->capacity, ss->size_class, slab_idx);
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tiny_failfast_abort_ptr("alloc_used_overflow",
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ss,
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slab_idx,
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block,
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"freelist_used_over_capacity");
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}
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}
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if (__builtin_expect(g_debug_remote_guard, 0)) {
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tiny_remote_track_on_alloc(ss, slab_idx, block, "freelist_alloc", 0);
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tiny_remote_assert_not_remote(ss, slab_idx, block, "freelist_alloc_ret", 0);
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}
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return block;
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}
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return NULL; // Slab is full
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}
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// Adopt helper: acquire → drain → bind (single boundary) – returns 1 on success
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static inline int adopt_bind_if_safe(TinyTLSSlab* tls, SuperSlab* ss, int slab_idx, int class_idx) {
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uint32_t self_tid = tiny_self_u32();
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SlabHandle h = slab_try_acquire(ss, slab_idx, self_tid);
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if (!slab_is_valid(&h)) return 0;
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slab_drain_remote_full(&h);
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if (__builtin_expect(slab_is_safe_to_bind(&h), 1)) {
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// Optional: move a few nodes to Front SLL to boost next hits
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tiny_drain_freelist_to_sll_once(h.ss, h.slab_idx, class_idx);
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tiny_tls_bind_slab(tls, h.ss, h.slab_idx);
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// Ownership now associated with TLS slab; release handle bookkeeping
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slab_release(&h);
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return 1;
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}
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slab_release(&h);
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return 0;
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}
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// Phase 6.24 & 7.6: Refill TLS SuperSlab (with unified TLS cache + deferred allocation)
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static SuperSlab* superslab_refill(int class_idx) {
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#if HAKMEM_DEBUG_COUNTERS
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g_superslab_refill_calls_dbg[class_idx]++;
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#endif
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TinyTLSSlab* tls = &g_tls_slabs[class_idx];
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// ============================================================================
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// Phase 2a: Dynamic Expansion - Initialize SuperSlabHead if needed
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// ============================================================================
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extern SuperSlabHead* g_superslab_heads[TINY_NUM_CLASSES_SS];
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extern SuperSlabHead* init_superslab_head(int class_idx);
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extern int expand_superslab_head(SuperSlabHead* head);
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SuperSlabHead* head = g_superslab_heads[class_idx];
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if (!head) {
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// First-time initialization for this class
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head = init_superslab_head(class_idx);
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if (!head) {
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extern __thread int g_hakmem_lock_depth;
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g_hakmem_lock_depth++;
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fprintf(stderr, "[DEBUG] superslab_refill: Failed to init SuperSlabHead for class %d\n", class_idx);
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g_hakmem_lock_depth--;
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return NULL; // Critical failure
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}
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g_superslab_heads[class_idx] = head;
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}
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// Try current chunk first (fast path)
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SuperSlab* current_chunk = head->current_chunk;
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if (current_chunk) {
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// Check if current chunk has available slabs
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// Bitmap semantics: 0=FREE, 1=OCCUPIED
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// - 0x00000000 = all free (32 available)
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// - 0xFFFFFFFF = all occupied (0 available)
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int chunk_cap = ss_slabs_capacity(current_chunk);
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uint32_t full_mask = (chunk_cap >= 32) ? 0xFFFFFFFF : ((1U << chunk_cap) - 1);
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if (current_chunk->slab_bitmap != full_mask) {
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// Current chunk has free slabs, use normal refill logic below
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// (Will be handled by existing code that checks tls->ss)
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if (tls->ss != current_chunk) {
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// Update TLS to point to current chunk
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tls->ss = current_chunk;
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}
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} else {
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// Current chunk exhausted (all slabs occupied), try to expand
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#if !defined(NDEBUG) || defined(HAKMEM_SUPERSLAB_VERBOSE)
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extern __thread int g_hakmem_lock_depth;
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g_hakmem_lock_depth++;
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fprintf(stderr, "[HAKMEM] SuperSlab chunk exhausted for class %d (bitmap=0x%08x), expanding...\n",
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class_idx, current_chunk->slab_bitmap);
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g_hakmem_lock_depth--;
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#endif
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// Protect expansion with global lock (race condition fix)
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static pthread_mutex_t expand_lock = PTHREAD_MUTEX_INITIALIZER;
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pthread_mutex_lock(&expand_lock);
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// Re-check after acquiring lock (another thread may have expanded)
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current_chunk = head->current_chunk;
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uint32_t recheck_mask = (ss_slabs_capacity(current_chunk) >= 32) ? 0xFFFFFFFF :
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((1U << ss_slabs_capacity(current_chunk)) - 1);
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if (current_chunk->slab_bitmap == recheck_mask) {
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// Still exhausted, expand now
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if (expand_superslab_head(head) < 0) {
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pthread_mutex_unlock(&expand_lock);
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#if !defined(NDEBUG) || defined(HAKMEM_SUPERSLAB_VERBOSE)
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g_hakmem_lock_depth++;
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fprintf(stderr, "[HAKMEM] CRITICAL: Failed to expand SuperSlabHead for class %d (system OOM)\n", class_idx);
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g_hakmem_lock_depth--;
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#endif
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return NULL; // True system OOM
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}
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#if !defined(NDEBUG) || defined(HAKMEM_SUPERSLAB_VERBOSE)
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g_hakmem_lock_depth++;
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fprintf(stderr, "[HAKMEM] Successfully expanded SuperSlabHead for class %d\n", class_idx);
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g_hakmem_lock_depth--;
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#endif
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}
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// Update current_chunk and tls->ss to point to (potentially new) chunk
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current_chunk = head->current_chunk;
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tls->ss = current_chunk;
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pthread_mutex_unlock(&expand_lock);
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// Verify chunk has free slabs
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full_mask = (ss_slabs_capacity(current_chunk) >= 32) ? 0xFFFFFFFF :
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((1U << ss_slabs_capacity(current_chunk)) - 1);
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if (!current_chunk || current_chunk->slab_bitmap == full_mask) {
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#if !defined(NDEBUG) || defined(HAKMEM_SUPERSLAB_VERBOSE)
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g_hakmem_lock_depth++;
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fprintf(stderr, "[HAKMEM] CRITICAL: Chunk still has no free slabs for class %d after expansion\n", class_idx);
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g_hakmem_lock_depth--;
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#endif
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return NULL;
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}
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}
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}
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// ============================================================================
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// Continue with existing refill logic
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// ============================================================================
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static int g_ss_adopt_en = -1; // env: HAKMEM_TINY_SS_ADOPT=1; default auto-on if remote seen
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if (g_ss_adopt_en == -1) {
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char* e = getenv("HAKMEM_TINY_SS_ADOPT");
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if (e) {
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g_ss_adopt_en = (*e != '0') ? 1 : 0;
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} else {
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extern _Atomic int g_ss_remote_seen;
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g_ss_adopt_en = (atomic_load_explicit(&g_ss_remote_seen, memory_order_relaxed) != 0) ? 1 : 0;
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}
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}
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extern int g_adopt_cool_period;
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extern __thread int g_tls_adopt_cd[];
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if (g_adopt_cool_period == -1) {
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char* cd = getenv("HAKMEM_TINY_SS_ADOPT_COOLDOWN");
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int v = (cd ? atoi(cd) : 0);
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if (v < 0) v = 0; if (v > 1024) v = 1024;
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g_adopt_cool_period = v;
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}
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static int g_superslab_refill_debug_once = 0;
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SuperSlab* prev_ss = tls->ss;
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TinySlabMeta* prev_meta = tls->meta;
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uint8_t prev_slab_idx = tls->slab_idx;
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uint8_t prev_active = prev_ss ? prev_ss->active_slabs : 0;
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uint32_t prev_bitmap = prev_ss ? prev_ss->slab_bitmap : 0;
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uint32_t prev_meta_used = prev_meta ? prev_meta->used : 0;
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uint32_t prev_meta_cap = prev_meta ? prev_meta->capacity : 0;
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int free_idx_attempted = -2; // -2 = not evaluated, -1 = none, >=0 = chosen
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int reused_slabs = 0;
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// Optional: Mid-size simple refill to avoid multi-layer scans (class>=4)
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do {
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static int g_mid_simple_warn = 0;
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if (class_idx >= 4 && tiny_mid_refill_simple_enabled()) {
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// If current TLS has a SuperSlab, prefer taking a virgin slab directly
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if (tls->ss) {
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int tls_cap = ss_slabs_capacity(tls->ss);
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if (tls->ss->active_slabs < tls_cap) {
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int free_idx = superslab_find_free_slab(tls->ss);
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if (free_idx >= 0) {
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uint32_t my_tid = tiny_self_u32();
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superslab_init_slab(tls->ss, free_idx, g_tiny_class_sizes[class_idx], my_tid);
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tiny_tls_bind_slab(tls, tls->ss, free_idx);
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return tls->ss;
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}
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}
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}
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// Otherwise allocate a fresh SuperSlab and bind first slab
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SuperSlab* ssn = superslab_allocate((uint8_t)class_idx);
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if (!ssn) {
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if (!g_superslab_refill_debug_once && g_mid_simple_warn < 2) {
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g_mid_simple_warn++;
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int err = errno;
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fprintf(stderr, "[DEBUG] mid_simple_refill OOM class=%d errno=%d\n", class_idx, err);
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}
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return NULL;
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}
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uint32_t my_tid = tiny_self_u32();
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superslab_init_slab(ssn, 0, g_tiny_class_sizes[class_idx], my_tid);
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SuperSlab* old = tls->ss;
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tiny_tls_bind_slab(tls, ssn, 0);
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superslab_ref_inc(ssn);
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if (old && old != ssn) { superslab_ref_dec(old); }
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return ssn;
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}
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} while (0);
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// First, try to adopt a published partial SuperSlab for this class
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if (g_ss_adopt_en) {
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if (g_adopt_cool_period > 0) {
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if (g_tls_adopt_cd[class_idx] > 0) {
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g_tls_adopt_cd[class_idx]--;
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} else {
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// eligible to adopt
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}
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}
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if (g_adopt_cool_period == 0 || g_tls_adopt_cd[class_idx] == 0) {
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SuperSlab* adopt = ss_partial_adopt(class_idx);
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if (adopt && adopt->magic == SUPERSLAB_MAGIC) {
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// ========================================================================
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// Quick Win #2: First-Fit Adopt (vs Best-Fit scoring all 32 slabs)
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// For Larson, any slab with freelist works - no need to score all 32!
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// Expected improvement: -3,000 cycles (from 32 atomic loads + 32 scores)
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// ========================================================================
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int adopt_cap = ss_slabs_capacity(adopt);
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int best = -1;
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for (int s = 0; s < adopt_cap; s++) {
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TinySlabMeta* m = &adopt->slabs[s];
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// Quick check: Does this slab have a freelist?
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if (m->freelist) {
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// Yes! Try to acquire it immediately (first-fit)
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best = s;
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break; // ✅ OPTIMIZATION: Stop at first slab with freelist!
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}
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// Optional: Also check remote_heads if we want to prioritize those
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// (But for Larson, freelist is sufficient)
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}
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if (best >= 0) {
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if (adopt_bind_if_safe(tls, adopt, best, class_idx)) {
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if (g_adopt_cool_period > 0) g_tls_adopt_cd[class_idx] = g_adopt_cool_period;
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return adopt;
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}
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}
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// If no freelist found, ignore and continue (optional: republish)
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}
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}
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}
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// Phase 7.6 Step 4: Check existing SuperSlab with priority order
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if (tls->ss) {
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// Priority 1: Reuse slabs with freelist (already freed blocks)
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int tls_cap = ss_slabs_capacity(tls->ss);
|
||
uint32_t nonempty_mask = 0;
|
||
do {
|
||
static int g_mask_en = -1;
|
||
if (__builtin_expect(g_mask_en == -1, 0)) {
|
||
const char* e = getenv("HAKMEM_TINY_FREELIST_MASK");
|
||
g_mask_en = (e && *e && *e != '0') ? 1 : 0;
|
||
}
|
||
if (__builtin_expect(g_mask_en, 0)) {
|
||
nonempty_mask = atomic_load_explicit(&tls->ss->freelist_mask, memory_order_acquire);
|
||
break;
|
||
}
|
||
for (int i = 0; i < tls_cap; i++) {
|
||
if (tls->ss->slabs[i].freelist) nonempty_mask |= (1u << i);
|
||
}
|
||
} while (0);
|
||
|
||
// O(1) lookup: scan mask with ctz (1 instruction!)
|
||
while (__builtin_expect(nonempty_mask != 0, 1)) {
|
||
int i = __builtin_ctz(nonempty_mask); // Find first non-empty slab (O(1))
|
||
nonempty_mask &= ~(1u << i); // Clear bit for next iteration
|
||
|
||
// FIX #1 DELETED (Race condition fix):
|
||
// Previous drain without ownership caused concurrent freelist corruption.
|
||
// Ownership protocol: MUST bind+owner_cas BEFORE drain (see Fix #3 in tiny_refill.h).
|
||
// Remote frees will be drained when the slab is adopted (see tiny_refill.h paths).
|
||
|
||
if (adopt_bind_if_safe(tls, tls->ss, i, class_idx)) {
|
||
reused_slabs = 1;
|
||
return tls->ss;
|
||
}
|
||
}
|
||
|
||
// Priority 2: Use unused slabs (virgin slabs)
|
||
if (tls->ss->active_slabs < tls_cap) {
|
||
// Find next free slab
|
||
int free_idx = superslab_find_free_slab(tls->ss);
|
||
free_idx_attempted = free_idx;
|
||
if (free_idx >= 0) {
|
||
// Initialize this slab
|
||
uint32_t my_tid = tiny_self_u32();
|
||
superslab_init_slab(tls->ss, free_idx, g_tiny_class_sizes[class_idx], my_tid);
|
||
|
||
// Update TLS cache (unified update)
|
||
tiny_tls_bind_slab(tls, tls->ss, free_idx);
|
||
|
||
return tls->ss;
|
||
}
|
||
}
|
||
}
|
||
|
||
// Try to adopt a partial SuperSlab from registry (one-shot, cheap scan)
|
||
// This reduces pressure to allocate new SS when other threads freed blocks.
|
||
// Phase 6: Registry Optimization - Use per-class registry for O(class_size) scan
|
||
if (!tls->ss) {
|
||
// Phase 6: Use per-class registry (262K → ~10-100 entries per class!)
|
||
extern SuperSlab* g_super_reg_by_class[TINY_NUM_CLASSES][SUPER_REG_PER_CLASS];
|
||
extern int g_super_reg_class_size[TINY_NUM_CLASSES];
|
||
|
||
const int scan_max = tiny_reg_scan_max();
|
||
int reg_size = g_super_reg_class_size[class_idx];
|
||
int scan_limit = (scan_max < reg_size) ? scan_max : reg_size;
|
||
|
||
for (int i = 0; i < scan_limit; i++) {
|
||
SuperSlab* ss = g_super_reg_by_class[class_idx][i];
|
||
if (!ss || ss->magic != SUPERSLAB_MAGIC) continue;
|
||
// Note: class_idx check is not needed (per-class registry!)
|
||
|
||
// Pick first slab with freelist (Box 4: adopt boundary helper)
|
||
int reg_cap = ss_slabs_capacity(ss);
|
||
for (int s = 0; s < reg_cap; s++) {
|
||
if (ss->slabs[s].freelist) {
|
||
if (adopt_bind_if_safe(tls, ss, s, class_idx)) return ss;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Must-adopt-before-mmap gate: attempt sticky/hot/bench/mailbox/registry small-window
|
||
{
|
||
SuperSlab* gate_ss = tiny_must_adopt_gate(class_idx, tls);
|
||
if (gate_ss) return gate_ss;
|
||
}
|
||
|
||
// Allocate new SuperSlab
|
||
SuperSlab* ss = superslab_allocate((uint8_t)class_idx);
|
||
if (!ss) {
|
||
if (!g_superslab_refill_debug_once) {
|
||
g_superslab_refill_debug_once = 1;
|
||
int err = errno;
|
||
|
||
// CRITICAL FIX (BUG #11): Protect fprintf() with lock_depth
|
||
// fprintf() can call malloc for buffering → must use libc malloc
|
||
extern __thread int g_hakmem_lock_depth;
|
||
g_hakmem_lock_depth++;
|
||
|
||
fprintf(stderr,
|
||
"[DEBUG] superslab_refill returned NULL (OOM) detail: class=%d prev_ss=%p active=%u bitmap=0x%08x prev_meta=%p used=%u cap=%u slab_idx=%u reused_freelist=%d free_idx=%d errno=%d\n",
|
||
class_idx,
|
||
(void*)prev_ss,
|
||
(unsigned)prev_active,
|
||
prev_bitmap,
|
||
(void*)prev_meta,
|
||
(unsigned)prev_meta_used,
|
||
(unsigned)prev_meta_cap,
|
||
(unsigned)prev_slab_idx,
|
||
reused_slabs,
|
||
free_idx_attempted,
|
||
err);
|
||
|
||
g_hakmem_lock_depth--;
|
||
}
|
||
// Clear errno to avoid confusion in fallback paths
|
||
errno = 0;
|
||
return NULL; // OOM
|
||
}
|
||
|
||
// Initialize first slab
|
||
uint32_t my_tid = tiny_self_u32();
|
||
superslab_init_slab(ss, 0, g_tiny_class_sizes[class_idx], my_tid);
|
||
|
||
// Cache in unified TLS（前のSS参照を解放）
|
||
SuperSlab* old = tls->ss;
|
||
tiny_tls_bind_slab(tls, ss, 0);
|
||
// Maintain refcount（将来の空回収に備え、TLS参照をカウント）
|
||
superslab_ref_inc(ss);
|
||
if (old && old != ss) {
|
||
superslab_ref_dec(old);
|
||
}
|
||
|
||
return ss;
|
||
}
|
||
|
||
// Phase 6.24: SuperSlab-based allocation (TLS unified, Medium fix)
|
||
static inline void* hak_tiny_alloc_superslab(int class_idx) {
|
||
// DEBUG: Function entry trace (gated to avoid ring spam)
|
||
do {
|
||
static int g_alloc_ring = -1;
|
||
if (__builtin_expect(g_alloc_ring == -1, 0)) {
|
||
const char* e = getenv("HAKMEM_TINY_ALLOC_RING");
|
||
g_alloc_ring = (e && *e && *e != '0') ? 1 : 0;
|
||
}
|
||
if (g_alloc_ring) {
|
||
tiny_debug_ring_record(TINY_RING_EVENT_ALLOC_ENTER, 0x01, (void*)(uintptr_t)class_idx, 0);
|
||
}
|
||
} while (0);
|
||
|
||
// MidTC fast path: 128..1024B（class>=4）はTLS tcacheを最優先
|
||
do {
|
||
void* mp = midtc_pop(class_idx);
|
||
if (mp) {
|
||
HAK_RET_ALLOC(class_idx, mp);
|
||
}
|
||
} while (0);
|
||
|
||
// Phase 6.24: 1 TLS read (down from 3)
|
||
TinyTLSSlab* tls = &g_tls_slabs[class_idx];
|
||
|
||
TinySlabMeta* meta = tls->meta;
|
||
int slab_idx = tls->slab_idx;
|
||
if (meta && slab_idx >= 0 && tls->ss) {
|
||
// CRITICAL: Verify class consistency BEFORE using tls->ss
|
||
// If tls->ss->size_class != class_idx, unbind and refill
|
||
if (tls->ss->size_class != class_idx) {
|
||
// Class mismatch: TLS is bound to wrong SuperSlab
|
||
// This happens when TLS was previously bound to different class
|
||
tls->ss = NULL;
|
||
tls->meta = NULL;
|
||
tls->slab_idx = -1;
|
||
tls->slab_base = NULL;
|
||
meta = NULL; // Force refill path below
|
||
} else {
|
||
// Ensure TLS view is consistent with canonical slab_base
|
||
uint8_t* canonical = tiny_slab_base_for(tls->ss, slab_idx);
|
||
if (tls->slab_base != canonical) {
|
||
tls->slab_base = canonical;
|
||
}
|
||
}
|
||
// A/B: Relaxed read for remote head presence check
|
||
static int g_alloc_remote_relax = -1; // env: HAKMEM_TINY_ALLOC_REMOTE_RELAX=1 → relaxed
|
||
if (__builtin_expect(g_alloc_remote_relax == -1, 0)) {
|
||
const char* e = getenv("HAKMEM_TINY_ALLOC_REMOTE_RELAX");
|
||
g_alloc_remote_relax = (e && *e && *e != '0') ? 1 : 0;
|
||
}
|
||
uintptr_t pending = atomic_load_explicit(&tls->ss->remote_heads[slab_idx],
|
||
g_alloc_remote_relax ? memory_order_relaxed
|
||
: memory_order_acquire);
|
||
if (__builtin_expect(pending != 0, 0)) {
|
||
uint32_t self_tid = tiny_self_u32();
|
||
if (ss_owner_try_acquire(meta, self_tid)) {
|
||
_ss_remote_drain_to_freelist_unsafe(tls->ss, slab_idx, meta);
|
||
}
|
||
}
|
||
}
|
||
|
||
// FIX #2 DELETED (Race condition fix):
|
||
// Previous drain-all-slabs without ownership caused concurrent freelist corruption.
|
||
// Problem: Thread A owns slab 5, Thread B drains all slabs including 5 → both modify freelist → crash.
|
||
// Ownership protocol: MUST bind+owner_cas BEFORE drain (see Fix #3 in tiny_refill.h).
|
||
// Remote frees will be drained when the slab is adopted via refill paths.
|
||
|
||
// Fast path: Direct metadata access (no repeated TLS reads!)
|
||
if (meta && meta->freelist == NULL && meta->used < meta->capacity && tls->slab_base) {
|
||
// Linear allocation (lazy init)
|
||
size_t block_size = g_tiny_class_sizes[tls->ss->size_class];
|
||
uint8_t* base = tls->slab_base; // tls_slab_base は tiny_slab_base_for(ss, slab_idx) 由来（唯一の真実）
|
||
|
||
// ULTRATHINK DEBUG: Capture the 53-byte mystery
|
||
if (tiny_refill_failfast_level() >= 3 && tls->ss->size_class == 7 && slab_idx == 0) {
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] === Before allocation ===\n");
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] ss=%p, slab_idx=%d, class=%d\n",
|
||
tls->ss, slab_idx, tls->ss->size_class);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] block_size=%zu, meta->used=%d, meta->capacity=%d\n",
|
||
block_size, meta->used, meta->capacity);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] tls->slab_base=%p\n", base);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] tiny_slab_base_for(ss,%d)=%p\n",
|
||
slab_idx, tiny_slab_base_for(tls->ss, slab_idx));
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] sizeof(SuperSlab)=%zu\n", sizeof(SuperSlab));
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] Expected base should be: ss + %zu\n", sizeof(SuperSlab));
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] Actual base is: ss + 1024\n");
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] Base error: %zu - 1024 = %zu bytes\n",
|
||
sizeof(SuperSlab), sizeof(SuperSlab) - 1024);
|
||
}
|
||
|
||
void* block = (void*)(base + ((size_t)meta->used * block_size));
|
||
|
||
// ULTRATHINK DEBUG: After calculation
|
||
if (tiny_refill_failfast_level() >= 3 && tls->ss->size_class == 7 && slab_idx == 0) {
|
||
size_t offset_from_ss = (uintptr_t)block - (uintptr_t)tls->ss;
|
||
size_t expected_offset = 1024 + ((size_t)meta->used * block_size);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] === Calculated block address ===\n");
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] block=%p\n", block);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] offset from ss=%zu (0x%zx)\n", offset_from_ss, offset_from_ss);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] expected offset=%zu (0x%zx)\n", expected_offset, expected_offset);
|
||
fprintf(stderr, "[ULTRA_53_DEBUG] difference=%zd bytes\n",
|
||
(ssize_t)offset_from_ss - (ssize_t)expected_offset);
|
||
}
|
||
|
||
meta->used++;
|
||
|
||
// Fail-Fast: self-check（デバッグ時のみ有効）
|
||
if (__builtin_expect(tiny_refill_failfast_level() >= 2, 0)) {
|
||
uintptr_t base_ss = (uintptr_t)tls->ss;
|
||
size_t ss_size = (size_t)1ULL << tls->ss->lg_size;
|
||
uintptr_t limit_ss = base_ss + ss_size;
|
||
uintptr_t p = (uintptr_t)block;
|
||
size_t off = (p >= base_ss) ? (size_t)(p - base_ss) : 0;
|
||
int in_range = (p >= base_ss) && (p < limit_ss);
|
||
int aligned = ((p - (uintptr_t)base) % block_size) == 0;
|
||
int idx_ok = (tls->slab_idx >= 0) && (tls->slab_idx < ss_slabs_capacity(tls->ss));
|
||
if (!in_range || !aligned || !idx_ok || meta->used > (uint32_t)meta->capacity) {
|
||
// Diagnostic log before abort
|
||
fprintf(stderr, "[ALLOC_CARVE_BUG] cls=%u slab=%d used=%u cap=%u base=%p bs=%zu ptr=%p offset=%zu\n",
|
||
tls->ss->size_class, tls->slab_idx, meta->used, meta->capacity,
|
||
(void*)base, block_size, block, off);
|
||
fprintf(stderr, "[ALLOC_CARVE_BUG] in_range=%d aligned=%d idx_ok=%d used_check=%d\n",
|
||
in_range, aligned, idx_ok, meta->used > (uint32_t)meta->capacity);
|
||
fflush(stderr);
|
||
|
||
tiny_failfast_abort_ptr("alloc_ret_align",
|
||
tls->ss,
|
||
tls->slab_idx,
|
||
block,
|
||
!in_range ? "out_of_range"
|
||
: (!aligned ? "misaligned"
|
||
: (!idx_ok ? "bad_slab_idx"
|
||
: "over_capacity")));
|
||
}
|
||
}
|
||
|
||
// Track active blocks in SuperSlab for conservative reclamation
|
||
ss_active_inc(tls->ss);
|
||
// Route: slab linear
|
||
ROUTE_MARK(11); ROUTE_COMMIT(class_idx, 0x60);
|
||
HAK_RET_ALLOC(class_idx, block); // Phase 8.4: Zero hot-path overhead
|
||
}
|
||
|
||
if (meta && meta->freelist) {
|
||
// Freelist allocation
|
||
void* block = meta->freelist;
|
||
// Safety: bounds/alignment check (debug)
|
||
if (__builtin_expect(g_tiny_safe_free, 0)) {
|
||
size_t blk = g_tiny_class_sizes[tls->ss->size_class];
|
||
uint8_t* base = tiny_slab_base_for(tls->ss, tls->slab_idx);
|
||
uintptr_t delta = (uintptr_t)block - (uintptr_t)base;
|
||
int align_ok = ((delta % blk) == 0);
|
||
int range_ok = (delta / blk) < meta->capacity;
|
||
if (!align_ok || !range_ok) {
|
||
uintptr_t info = ((uintptr_t)(align_ok ? 1u : 0u) << 32) | (uint32_t)(range_ok ? 1u : 0u);
|
||
tiny_debug_ring_record(TINY_RING_EVENT_REMOTE_INVALID, (uint16_t)tls->ss->size_class, block, info | 0xA100u);
|
||
if (g_tiny_safe_free_strict) { raise(SIGUSR2); return NULL; }
|
||
return NULL;
|
||
}
|
||
}
|
||
void* next = *(void**)block;
|
||
meta->freelist = next;
|
||
meta->used++;
|
||
// Optional: clear freelist bit when becomes empty
|
||
do {
|
||
static int g_mask_en = -1;
|
||
if (__builtin_expect(g_mask_en == -1, 0)) {
|
||
const char* e = getenv("HAKMEM_TINY_FREELIST_MASK");
|
||
g_mask_en = (e && *e && *e != '0') ? 1 : 0;
|
||
}
|
||
if (__builtin_expect(g_mask_en, 0) && next == NULL) {
|
||
uint32_t bit = (1u << slab_idx);
|
||
atomic_fetch_and_explicit(&tls->ss->freelist_mask, ~bit, memory_order_release);
|
||
}
|
||
} while (0);
|
||
// Track active blocks in SuperSlab for conservative reclamation
|
||
ss_active_inc(tls->ss);
|
||
// Route: slab freelist
|
||
ROUTE_MARK(12); ROUTE_COMMIT(class_idx, 0x61);
|
||
HAK_RET_ALLOC(class_idx, block); // Phase 8.4: Zero hot-path overhead
|
||
}
|
||
|
||
// Slow path: Refill TLS slab
|
||
SuperSlab* ss = superslab_refill(class_idx);
|
||
if (!ss) {
|
||
static int log_oom = 0;
|
||
if (log_oom < 2) { fprintf(stderr, "[DEBUG] superslab_refill returned NULL (OOM)\n"); log_oom++; }
|
||
return NULL; // OOM
|
||
}
|
||
|
||
// Retry allocation (metadata already cached in superslab_refill)
|
||
meta = tls->meta;
|
||
|
||
// DEBUG: Check each condition (disabled for benchmarks)
|
||
// static int log_retry = 0;
|
||
// if (log_retry < 2) {
|
||
// fprintf(stderr, "[DEBUG] Retry alloc: meta=%p, freelist=%p, used=%u, capacity=%u, slab_base=%p\n",
|
||
// (void*)meta, meta ? meta->freelist : NULL,
|
||
// meta ? meta->used : 0, meta ? meta->capacity : 0,
|
||
// (void*)tls->slab_base);
|
||
// log_retry++;
|
||
// }
|
||
|
||
if (meta && meta->freelist == NULL && meta->used < meta->capacity && tls->slab_base) {
|
||
size_t block_size = g_tiny_class_sizes[ss->size_class];
|
||
void* block = (void*)(tls->slab_base + ((size_t)meta->used * block_size));
|
||
|
||
// Disabled for benchmarks
|
||
// static int log_success = 0;
|
||
// if (log_success < 2) {
|
||
// fprintf(stderr, "[DEBUG] Superslab alloc SUCCESS: ptr=%p, class=%d, used=%u->%u\n",
|
||
// block, class_idx, meta->used, meta->used + 1);
|
||
// log_success++;
|
||
// }
|
||
|
||
meta->used++;
|
||
// Track active blocks in SuperSlab for conservative reclamation
|
||
ss_active_inc(ss);
|
||
HAK_RET_ALLOC(class_idx, block); // Phase 8.4: Zero hot-path overhead
|
||
}
|
||
|
||
// Disabled for benchmarks
|
||
// static int log_fail = 0;
|
||
// if (log_fail < 2) {
|
||
// fprintf(stderr, "[DEBUG] Retry alloc FAILED - returning NULL\n");
|
||
// log_fail++;
|
||
// }
|
||
return NULL;
|
||
}
|