Intel® 64 and IA-32 Architectures Optimization Reference Manual

USING PERFORMANCE MONITORING EVENTSMetricAll WC Underwayfrom the processor 2Bus WritesUnderway from theprocessor 2Table B-5. Performance Metrics - Bus (Contd.)DescriptionAccrued sum of thedurations of all WCtransactions by thisprocessor.Divide by “All WC fromthe processor” to getWC request latency.Also beware ofdifferent recipes inmask bits for Pentium4 and Intel Xeonprocessors betweenCPUID model fieldvalue of 2 and modelvalue less than 2.Accrued sum of thedurations of all writetransactions by thisprocessorDivide by “Writes fromthe Processor” to getbus write requestlatency.Also beware ofdifferent recipes inmask bits for Pentium4 and Intel Xeonprocessors betweenCPUID model fieldvalue of 2 and modelvalue less than 2.Event Name or MetricExpressionIOQ_active_entriesIOQ_active_entriesEvent Mask ValueRequired1a. ReqA0, MEM_WC,OWN (CPUID model = 2)1a. 1a. ReqA0,ALL_WRITE, OWN(CPUID model < 2);1b. ReqA0, ALL_WRITE,MEM_WB, MEM_WT,MEM_WP, MEM_WC,MEM_UC, OWN(CPUID model >= 2).B-23