itlb Measurement Report Description

With the itlb measurement, produced by the itlb measurement configuration file, HP Caliper measures and reports two levels of information:

Exact counts of instruction translation lookaside buffer (TLB) metrics summed across the entire run of an application

Sampled instruction TLB metrics that are associated with particular locations in the application The report shows masured data by thread, load module, function, statement, and cache line.

Command-line options allow you to control the amount of data reported, how the data is sorted, and the number of statements and instructions reported for each sampled program location.

Example Command Line for Text Report

$ caliper itlb -o reports/itlbm.txt ./matmul

Example Command Line for CSV Report

$ caliper itlb --csv csvout ./matmul

itlb Metrics Summed for Entire Run

This section describes the metrics summed over the entire run of your application under HP Caliper.

Metrics for Integrity Servers Itanium 2 Systems

L1I_READS

The number of data memory read references issued into the

 

memory pipeline that are serviced by L1D (only integer

 

loads), RSE loads, L1-hinted loads (L1D returns data if it hits

 

in L1D but does not do a fill), and check loads (ld.c).

 

Non-cacheable reads, VHPT loads, semaphores,

 

floating-point loads, and lfetch instructions are not counted

 

here because L1D does not handle these. The count includes

 

wrong path operations but excludes predicated off

 

operations.

ITLB_MISSES_FETCH.L1ITLB

Number of L1 instruction TLB misses for demand fetch.

 

Misses are counted even if the L1 instruction TLB is not

 

updated for an access (non-cacheable/nat page/not present

 

page/faulting/some flushed), it will be counted here.

ITLB_MISSES_FETCH.L2ITLB

Number of L1 instruction TLB misses that also missed in the

 

L2 instruction TLB.

Total L1 Instruction TLB References

Total number of L1 instruction TLB references.

L1 Instruction TLB Miss Ratio

Ratio of L1 instruction TLB misses to Total L1 instruction TLB

 

references.

Metrics for Integrity Servers Dual-Core Itanium 2 and Itanium 9300 Quad-Core Processor Systems

BACK_END_BUBBLE.ALL

Number of cycles when the back end of the pipeline was

 

stalled. This is the number of cycles lost (stall cycles) due to

 

any of five possible events (FPU/L1D, RSE, EXE,

 

branch/exception, or the front end).

BACK_END_BUBBLE.FE

Full Pipe Bubbles in Main Pipe due to front end. This is the

 

number of cycles lost (stall cycles) due to ICACHE ITLB and

 

branch execution stalls.

BE_LOST_BW_DUE_TO_FE.ALL

Number of invalid bundles at the exit from Instruction Buffer

 

only if the back end is not stalled for other reasons.

208 Descriptions of Measurement Reports

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HP UX Caliper Software Itlb Measurement Report Description, Itlb Metrics Summed for Entire Run, ITLBMISSESFETCH.L1ITLB