50 lines
1.7 KiB
C
50 lines
1.7 KiB
C
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// hakmem_batch.h - madvise Batching for TLB Optimization (Box Theory)
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//
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// Priority 3 optimization from ChatGPT Pro feedback:
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// Batch MADV_DONTNEED calls to reduce TLB flush overhead
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//
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// Why batching matters:
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// - mimalloc is 2× faster on VM scenario partly due to batched madvise
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// - Each madvise() call triggers TLB flush (expensive!)
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// - Batching 4MB worth of blocks reduces TLB flushes by 50-100×
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//
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// Expected Gain: +20-30% on VM scenario
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#pragma once
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#include <stddef.h>
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#include <stdint.h>
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// Configuration
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#define BATCH_THRESHOLD (8 * 1024 * 1024) // 8MB: flush batch when reached (Phase 6.11: increased from 1MB for 2MB allocations)
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#define BATCH_MIN_SIZE (64 * 1024) // 64KB: only batch large blocks
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#define BATCH_MAX_BLOCKS 256 // Max blocks in batch
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// Batch state
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typedef struct {
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void* blocks[BATCH_MAX_BLOCKS]; // Pointers to blocks
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size_t sizes[BATCH_MAX_BLOCKS]; // Sizes of blocks
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int count; // Number of blocks in batch
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size_t total_bytes; // Total bytes in batch
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} DontneedBatch;
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// Batching API (Box Interface)
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void hak_batch_init(void);
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void hak_batch_shutdown(void);
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// Add block to batch (returns 1 if flushed, 0 if buffered)
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int hak_batch_add(void* ptr, size_t size);
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// Force flush all batched blocks
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void hak_batch_flush(void);
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// Statistics
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void hak_batch_print_stats(void);
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// Query
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size_t hak_batch_get_pending_bytes(void);
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int hak_batch_get_pending_count(void);
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// Page-level DONTNEED batching (for managed pool pages): enqueue whole pages
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// Flush performs MADV_DONTNEED only (no munmap), safe with retained VA pointers.
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int hak_batch_add_page(void* page, size_t size);
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