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Performance improvement: prevent false sharing #9

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Performance improvement: prevent false sharing #9

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11 changes: 8 additions & 3 deletions benchmark/DB_oindex.hh
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Original file line number Diff line number Diff line change
Expand Up @@ -773,7 +773,10 @@ protected:

private:
table_type table_;
uint64_t key_gen_;
union alignas(CACHE_LINE_SIZE) {
uint64_t key_gen_;
uint8_t _[CACHE_LINE_SIZE];
};

static bool
access_all(std::array<access_t, value_container_type::num_versions>& cell_accesses, std::array<TransItem*,
Expand Down Expand Up @@ -1450,8 +1453,10 @@ public:

//private:
table_type table_;
uint64_t key_gen_;

union alignas(CACHE_LINE_SIZE) {
uint64_t key_gen_;
uint8_t _[CACHE_LINE_SIZE];
};
//static bool
//access_all(std::array<access_t, internal_elem::num_versions>&, std::array<TransItem*, internal_elem::num_versions>&, internal_elem*) {
// always_assert(false, "Not implemented.");
Expand Down
11 changes: 8 additions & 3 deletions benchmark/DB_uindex.hh
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Original file line number Diff line number Diff line change
Expand Up @@ -84,8 +84,10 @@ private:
Hash hasher_;
Pred pred_;

uint64_t key_gen_;

union alignas(CACHE_LINE_SIZE) {
uint64_t key_gen_;
uint8_t _[CACHE_LINE_SIZE];
};
// used to mark whether a key is a bucket (for bucket version checks)
// or a pointer (which will always have the lower 3 bits as 0)
static constexpr uintptr_t bucket_bit = C::item_key_tag;
Expand Down Expand Up @@ -681,7 +683,10 @@ private:
Hash hasher_;
Pred pred_;

uint64_t key_gen_;
union alignas(CACHE_LINE_SIZE) {
uint64_t key_gen_;
uint8_t _[CACHE_LINE_SIZE];
};

// used to mark whether a key is a bucket (for bucket version checks)
// or a pointer (which will always have the lower 3 bits as 0)
Expand Down