If you use gkrellm, you'll get a plot of each core's activity so it's easy to see how many are being used.
yum install gkrellm. HTH On 07/01/2018 06:16 AM, Jeff Newmiller wrote: > Use "top" at the bash prompt. > > Read about the "mc.cores" parameter to mclapply. > > Make a simplified example version of your analysis and post your question in > the context of that example [1][2][3]. You will learn about the issues you > are dealing with in the process of trimming your problem, and will have code > you can share that demonstrates the issue without exposing private > information. > > Running parallel does not necessarily improve performance because other > factors like task switching overhead and Inter-process-communication (data > sharing) can drag it down. Read about the real benefits and drawbacks of > parallelism... there are many discussions out there out there... you might > start with [4]. > > > [1] > http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example > > [2] http://adv-r.had.co.nz/Reproducibility.html > > [3] https://cran.r-project.org/web/packages/reprex/index.html (read the > vignette) > > [4] > https://nceas.github.io/oss-lessons/parallel-computing-in-r/parallel-computing-in-r.html > > On June 30, 2018 10:07:49 AM PDT, akshay kulkarni <akshay...@hotmail.com> > wrote: >> dear members, >> I am using mclapply to parallelize my code. I am using Red Hat Linux in >> AWS. >> >> When I use mclapply, I see no speed increase. I doubt that the Linux OS >> is allowing fewer than the maximum number of cores to mclapply ( by >> default, mclapply takes all the available cores to it). >> >> How do you check if the number of workers is less than the output given >> by detectCores(), in Linux? Is there any R function for it? >> >> I do acknowledge that help on an OS is not suitable for this mailing >> list, but even Internet could'nt help me. Therefore this mail...... >> >> very many thanks for your time and effort... >> yours sincerely, >> AKSHAY M KULKARNI >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
