在Ubuntu的R中多核和内存的使用

I am running R on an Ubuntu workstation with 8 virtual cores and 8 Gb of ram. I was hoping to routinely use the multicore package to make use of the 8 cores in parallel; however I find that the whole R process becomes duplicated 8 times. As R actually seems to use much more memory than is reported in gc (by a factor 5, even after gc()), this means that even a relatively mild memory usage (one 200Mb object) becomes intractably memory-heavy once duplicated 8 times. I looked into bigmemory to have the child processes share the same memory space; but it would require some major rewriting of my code as it doesn't deal with dataframes.I am running R on an Ubuntu workstation with 8