[Rd] confint Attempts to Use All Server CPUs by Default

[Ben Bolker]

   Following up on this -- on my system, I have 69 packages installed 
that appear to provide something like a confint() method:

h <-  help.search("confint", agrep = FALSE)
p <- sort(unique(h$matches$Package))
length(p)
## [1] 69

p

  [1] "bamlss"          "bbmle"           "binom"           "brglm2" 

  [5] "broom"           "caper"           "car"             "CDM" 

  [9] "CLME"            "coin"            "crosstable"      "dclone" 

[13] "doBy"            "drc"             "Ecfun"           "emmeans"
[17] "epigrowthfit"    "evd"             "Exact"           "fitode"
[21] "fixest"          "ggfortify"       "ggplot2"         "GLMMadaptive"
[25] "glmmTMB"         "gratia"          "hdm"             "JMbayes"
[29] "JointAI"         "lava"            "lme4"            "lmeresampler"
[33] "lmtest"          "logistf"         "MASS"            "maxLik"
[37] "metafor"         "mitml"           "MKmisc"          "mmrm"
[41] "mosaic"          "MplusAutomation" "multcomp"        "ordinal"
[45] "papaja"          "parsnip"         "prodlim"         "R2admb"
[49] "rethinking"      "riskRegression"  "RSA"             "rstanarm"
[53] "rxode2"          "segmented"       "simr"            "sirt"
[57] "sn"              "spaMM"           "stats"           "stats4"
[61] "strucchange"     "survey"          "survival"        "systemfit"
[65] "TMB"             "unmarked"        "vegan"           "VGAM"
[69] "zipfR"

  If a confint() method were actually included in the package test 
suite, I would expect this kind of problem to be caught by CRAN checks 
(which look for code that is being greedy with parallelization). But 
it's perfectly possible that a package maintainer neglected to include 
such tests ...


On 2024-05-21 6:00 a.m., Ivan Krylov via R-devel wrote:
> В Tue, 21 May 2024 08:00:11 +0000
> Dario Strbenac via R-devel <r-devel using r-project.org> пишет:
> 
>> Would a less resource-intensive value, such as 1, be a safer default
>> CPU value for confint?
> 
> Which confint() method do you have in mind? There is at least four of
> them by default in R, and many additional classes could make use of
> stats:::confint.default by implementing vcov().
> 
>> Also, there is no mention of such parallel processing in ?confint, so
>> it was not clear at first where to look for performance degradation.
>> It could at least be described in the manual page so that users would
>> know that export OPENBLAS_NUM_THREADS=1 is a solution.
> 
> There isn't much R can do about the behaviour of the BLAS, because
> there is no standard interface to set the number of threads. Some BLASes
> (like ATLAS) don't even offer it as a tunable number at all [*].
> 
> A system administrator could link the installation of R against
> FlexiBLAS [**], provide safe defaults in the environment variables and
> educate the users about its tunables [***], but that's a choice just
> like it had been a choice to link R against a parallel variant of
> OpenBLAS on a shared computer. This is described in R Installation and
> Administration, section A.3.1 [****].
>