09-12-2013
Multithreading does not work that way; two cores can't cooperate to run a single-threaded program faster. Single-threaded programs will run slower on machines with lots of slower cores; we've had some puzzled folks ask us why their new machines have worse single-threaded benchmarks than their old ones.
But more cores means you can run more threads or processes at once without sharing time; more total work can be accomplished in the aggregate; but a program has to be designed with this in mind (or multiple instances of it run) to take advantage of this capability.
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LEARN ABOUT DEBIAN
runlim
RUNLIM(1) General Commands Manual RUNLIM(1)
NAME
runlim - a program to run benchmarks
SYNOPSIS
runlim [ options ...] command [ arguments ...]
DESCRIPTION
run is a tool that can be used to run and control benchmarks. It executes a given command with (optional) arguments, samples resource
usage during the run, and kills the process (and its child processes) if a certain time and/or space limit is exhausted.
Every 100 milliseconds, runlim takes a sample of the program's resource utilization, and logs status information to stderr every second.
Optionally, the status can be logged to a file.
Multi-threaded programs can be limited by setting a wall clock timeout. runlim follows the time accumulation scheme of GNU time for multi-
threaded programs and programs that spawn multiple child-processes: time spent in each thread/child is summed up, unless you are only
interested in walk clock time.
OPTIONS
runlim accepts the following options:
-h, --help
Show summary of options.
--version
Show version of program.
-o FILE, --output-file=FILE
Overwrite or create FILE for output logging.
-s NUM, --space-limit=NUM
Set space limit to NUM megabytes.
-t NUM, --time-limit=NUM
Set time limit to NUM seconds.
-r NUM, --real-time-limit=NUM
Set real time limit to NUM seconds.
-k, --kill
Propagate signals.
SEE ALSO
time(1), timelimit(1), timeout(1), time(7).
AUTHOR
runlim was written by Armin Biere and Toni Jussila.
This manual page was written by Thomas Krennwallner <tkren@kr.tuwien.ac.at>, for the Debian project (and may be used by others).
February 11, 2011 RUNLIM(1)