[R] BATCH jobs taking too much resources?

[Stuart Luppescu]

Is there something unusual about the way BATCH jobs are run? I ran a job
like this:
nice R CMD BATCH program.R

It ran for a little while and then it starting eating up huge amounts of
resources. Here is the entry from top:
top  17:34:10 up 36 days,  8:10,  4 users,  load average: 13.11, 6.85, 3.7 0
Tasks: 173 total,   6 running, 167 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.1%us, 99.4%sy,  0.0%ni,  0.0%id,  0.4%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  32712300k total, 32565372k used,   146928k free,      856k buffers
Swap: 34766840k total, 34766840k used,        0k free,     9812k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND       
                                                                
28829 lupp      26  10 53.3g  30g  128 R  7.9 98.6 134:23.54 R  

Note that it's taking about 54GB of memory. Right after this the load
average went up to over 23 and the system started killing off processes,
including mine. And this is on a system with 32GB of physical memory and
2 quad-core Xenon processors. 

However, when I run the job as an inferior process in emacs under ess,
it is very well behaved. Here is the output from top:

top - 22:22:48 up 37 days, 12:58,  1 user,  load average: 1.01, 1.04, 1.07
Tasks: 133 total,   2 running, 131 sleeping,   0 stopped,   0 zombie
Cpu(s): 25.0%us,  0.0%sy,  0.0%ni, 75.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  32712300k total, 31120472k used,  1591828k free,   466180k buffers
Swap: 34766840k total,    86160k used, 34680680k free, 10935976k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                 
 3768 lupp      25   0 17.8g  17g 4060 R 96.2 56.6 154:42.43 R                         

It only uses 17.8GB of memory and the load stays right around 1.0.
Admittedly, this is a rather big job: lmer with 2,200,000 records
crossed by 125,000 students and 10,000 teachers. But I don't understand
why it should consume resources so avariciously when run as a BATCH job.
Can anyone explain this to me?

TIA

-- 
Stuart Luppescu -*-*- slu <at> ccsr <dot> uchicago <dot> edu
CCSR in UEI at U of C