Difference between revisions of "ALUSaturation"
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(Created page with "== Description == The pattern "ALU saturation" describes the performance limitation caused by fully utilizing a functional unit inside a CPU core. == Symptoms == * Throughput...") |
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== Description == | == Description == | ||
The pattern "ALU saturation" describes the performance limitation caused by fully utilizing a functional unit inside a CPU core. | The pattern "ALU saturation" describes the performance limitation caused by fully utilizing a functional unit inside a CPU core. | ||
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== Detection == | == Detection == | ||
Use a hardware-counter tool like: | Use a hardware-counter tool like: | ||
| − | * LIKWID with performance groups FLOPS_SP, | + | * LIKWID with performance groups FLOPS_SP, FLOPS_DP, DATA and CLOCK |
| + | * Same information can be provided by perf or PAPI | ||
== Possible optimizations and/or fixes == | == Possible optimizations and/or fixes == | ||
Latest revision as of 16:13, 3 September 2019
Description
The pattern "ALU saturation" describes the performance limitation caused by fully utilizing a functional unit inside a CPU core.
Symptoms
- Throughput at design limit(s)
- Good (low) CPI
- Integral ratio of cycles to specific instruction count(s).
Detection
Use a hardware-counter tool like:
- LIKWID with performance groups FLOPS_SP, FLOPS_DP, DATA and CLOCK
- Same information can be provided by perf or PAPI