Intel® 64 and IA-32 Architectures Optimization Reference Manual

USING PERFORMANCE MONITORING EVENTSmance-monitoring events from which these bus and memory metrics are derived.The granularities of core references are listed below, according to the performancemonitoring events documented in Appendix A of Intel® 64 and IA-32 ArchitecturesSoftware Developer’s Manual, Volume 3B.B.2.2.1Reads due to program loads• BSQ_cache_reference — 128 bytes for misses (on current implementations),64 bytes for hits• BSQ_allocation — 128 bytes for hits or misses (on current implementations),smaller for partials' hits or misses• BSQ_active_entries — 64 bytes for hits or misses, smaller for partials' hits ormisses• IOQ_allocation, IOQ_active_entries — 64 bytes, smaller for partials' hits ormissesB.2.2.2Reads due to program writes (RFOs)• BSQ_cache_reference — 64 bytes for hits or misses• BSQ_allocation — 64 bytes for hits or misses (the granularity for misses maychange in future implementations of BSQ_allocation), smaller for partials' hits ormisses• BSQ_active_entries — 64 bytes for hits or misses, smaller for partials' hits ormisses• IOQ_allocation, IOQ_active_entries — 64 bytes for hits or misses, smaller forpartials' hits or missesB.2.2.3Writebacks (dirty evictions)• BSQ_cache_reference — 64 bytes• BSQ_allocation — 64 bytes• BSQ_active_entries — 64 bytes• IOQ_allocation, IOQ_active_entries — 64 bytesThe count of IOQ allocations may exceed the count of corresponding BSQ allocationson current implementations for several reasons, including:• Partials — In the FSB IOQ, any transaction smaller than 64 bytes is broken upinto one to eight partials, each being counted separately as a or one to eight-bytechunks. In the BSQ, allocations of partials get a count of one. Future implementationswill count each partial individually.• Different transaction sizes — Allocations of non-partial programmatic loadrequests get a count of one per 128 bytes in the BSQ on current implementations,and a count of one per 64 bytes in the FSB IOQ. Allocations of RFOs get aB-32