sys/benchmark: warm up cache #21407
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sys/benchmark: warm up cache #21407
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Add a few cycles before starting the stopwatch for fancy CPUs that do have a cache and branch predictor that may warm up (e.g. Cortex M7).
mguetschow
approved these changes
May 19, 2025
mguetschow
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the
CI: ready for build
It currently has no users. I'm not sure if the impact of this PR is noticeable. I should probably test on a Cortex M7. I recall that a Nucleo F767ZI is running a two instruction counting loop either in >10 CPU cycles or in 1 CPU cycle (due to the dual issue feature it can run up to two instructions simultaneously), depending on the branch predictor. I guess that will show if this PR has an impact on benchmarks that justifies the added complexity. |
crasbe
added
the
Type: enhancement
Murdock results❌ FAILED 15e8d0c sys/benchmark: warm up cache Build failures (1)
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Contribution description
Add a few cycles before starting the stopwatch for fancy CPUs that do have a cache and branch predictor that may warm up (e.g. Cortex M7).
Testing procedure
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Issues/PRs references
Split out of #21403