Commonly Used Metrics for Performance Analysis - Power.org

Metrics for Performance AnalysisUnit (either the Branch Unit or the CR unit).PM_CMPLU_STALL_LSUCompletion stall caused by LSU instructionFollowing a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes was from the Load Store Unit.PM_CMPLU_STALL_REJECT Completion stall caused by rejectFollowing a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes suffered a load/store reject.PM_CMPLU_STALL_SCALAR Completion stall caused by FPU instructionFollowing a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes was a scalar floating pointinstruction.PM_CMPLU_STALL_SCALAR_LONG Completion stall caused by long latency scalar instructionFollowing a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes was a floating point divide orsquare root instruction.PM_CMPLU_STALL_STORE Completion stall due to store instructionFollowing a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes was a store. This generallyhappens when we run out of real SRQ entries, which prevents stores from issuing.PM_CMPLU_STALL_THRDCompletion stall due to thread conflict. Group ready to complete butit was another thread's turn.Following a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the thread could not complete a group because the completion port it’s sharing wasbeing used by another thread. In SMT4 mode, Thread0 and thread2 share a completion port and Thread1and Thread3 share another completion port.PM_CMPLU_STALL_VECTOR Completion stall caused by Vector instructionFollowing a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes was a vector instruction.PM_CMPLU_STALL_VECTOR_LONG Completion stall due to long latency vector instruction.Following a completion stall (any period when no groups completed and the group completion table was notempty for that thread) the last instruction to finish before completion resumes was a long latency vectorinstruction.PM_GCT_NOSLOT_BR_MPRED GCT empty by branch mispredictionThese cycles occur when the Global Completion Table has no slots from this thread because of a branchmisprediction.PM_GCT_NOSLOT_BR_MPRED_IC_MISS GCT empty by branch misprediction + IC missThese cycles occur when the Global Completion Table has no slots from this thread because of a branchmisprediction and an instruction cache miss.PM_GCT_NOSLOT_CYCNo itags assignedThese cycles occur when the Global Completion Table has no slots from this thread.PM_GCT_NOSLOT_IC_MISS GCT empty by I-cache missThese cycles occur when the Global Completion Table has no slots from this thread because of an instructioncache miss.PM_GRP_CMPLGroup completedCopyright ©2011 IBM Corporation Page 18 of 52