chore: add Dash::Prefetch function #4476
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BorysTheDev
reviewed
Jan 19, 2025
BorysTheDev
reviewed
Jan 19, 2025
| const Bucket& target = bucket_[bidx]; | ||
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| // Prefetch the home bucket that might hold the key with high probability. | ||
| __builtin_prefetch(&target, 0, 1); |
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what is the bucket size? if the size of the bucket is more than the cache line maybe it will be better to load the whole bucket
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the bucket size is dependent on the key/value size but the bucket metadata is located at the beginning. we use the metadata/fingerprints to do the initial scan.
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Could you clarify what metadata do you want to read, because to my mind it's more than 64 bytes
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SlotBitmap<NUM_SLOTS> slotb_; // allocation bitmap + pointer bitmap + counter
/*only use the first 14 bytes, can be accelerated by
SSE instruction,0-13 for finger, 14-17 for overflowed*/
FpArray finger_arr_;
StashFpArray stash_arr_;
uint8_t stash_busy_ = 0; // kStashFpLen+1 bits are used
uint8_t stash_pos_ = 0; // 4x2 bits for pointing to stash bucket.
BucketBase<NUM_SLOTS, NUM_OVR>::CompareFP is the function that usually hits a cold memory
BorysTheDev
approved these changes
Jan 19, 2025
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