[R-pkg-devel] Issue "Re-building vignettes had CPU time 4.1 times elapsed time"

? Wed, 11 Feb 2026 10:15:39 +1100
Nicholas Tierney <nicholas.tierney at gmail.com> ?????:

Unfortunately I am unable to trigger this NOTE locally, even running:

```
_R_CHECK_VIGNETTE_TIMING_CPU_TO_ELAPSED_THRESHOLD_=1.1 \
 R CMD check --timings greta_0.5.1.tar.gz
```

What's your operating system? How many logical processors does it have?
Could it be offloading Tensorflow operations to a GPU? This check
doesn't work on Windows, but should be very sensitive otherwise.

I have tried setting default chains and cpu to be 2, but it seems,
based on your evidence perhaps that there is something inside
tensorflow, or in reticulate that might be triggering this.

Sorry, my mistake. Setting the number of chains to 2 instead of 4
seemed to lower the average CPU load closer to 2 on my computer, but
the instantaneous CPU load still spikes to around 400%. This is
definitely happening in the threads created by Tensorflow, see the
attached plot of approximate CPU load versus DLL name and process
runtime.

Best regards,
Ivan

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