OOMMF Home next up previous contents index
Next: Platform Specific Installation Issues Up: Installation Previous: Basic Installation

Subsections


Advanced Installation

The following sections provide instructions for some additional installation options.


Reducing Disk Space Usage

To delete the intermediate files created when building the OOMMF software from source code, use pimake to build the target objclean in the root directory of the OOMMF distribution.

tclsh oommf.tcl pimake objclean
Running your platform strip utility on the OOMMF executable files should also reduce their size somewhat.


Local Customizations

OOMMF software supports local customization of some of its features. All OOMMF programs load the file config/options.tcl, which contains customization commands as well as editing instructions. As it is distributed, config/options.tcl directs programs to also load the file config/local/options.tcl, if it exists. Because future OOMMF releases may overwrite the file config/options.tcl, permanent customizations should be made by copying config/options.tcl to config/local/options.tcl and editing the copy. It is recommended that you leave in the file config/local/options.tcl only the customization commands necessary to change those options you wish to modify. Remove all other options so that overwrites by subsequent OOMMF releases are allowed to change the default behavior.

Notable available customizations include the choice of which network port the host service directory application uses, and the choice of what program is used for the display of help documentation. By default, OOMMF software uses the application mmHelp, which is included in the OOMMF release, but the help documentation files are standard HTML, so any web browser may be used instead. Complete instructions are in the file config/options.tcl.


Optimization

In the interest of successful compilation of a usable software package ``out of the box,'' the default configuration for OOMMF does not attempt to achieve much in terms of optimization. However, in each platform's configuration file (for example, config/platforms/wintel.tcl), there are alternative values for the configuration's optimization flags, available as comments. If you are familiar with your compiler's command line options, you may experiment with other choices as well. You can edit the platform configuration file to replace the default selection with another choice that provides better computing performance. For example, in config/platforms/wintel.tcl, alternative optimization flags for the MSVC++ compiler may be invoked by editing how the configuration variable opts is defined, following instructions in the comments.

The extensible solver, Oxs, can be compiled with debugging support for extensive run-time code checks. This will significantly reduce computation performance. In the standard OOMMF distributions, these checks should be disabled. You may verify this by checking that the following line appears in the file config/options.tcl:

Oc_Option Add * Platform cflags {-def NDEBUG}
To enable these checks, either comment/remove this line, or else add to the config/local/options.tcl file a ``cflags'' option line without ``-def NDEBUG'', such as
Oc_Option Add * Platform cflags {-warn 1}
The config/local/options.tcl file may be created if it does not already exist.


Parallelization

The OOMMF Oxs 3D solvers (oxsii amd boxsi) can be built thread-enabled to allow parallel processing on multi-processor/multi-core machines. In order to build and run a parallel version of OOMMF, you must have a thread-enabled version of Tcl. Most standard binary releases of Tcl today are thread-enabled, so OOMMF releases that include pre-built executables are built thread-enabled. If you build OOMMF from source, then by default OOMMF will be built thread-enabled if your Tcl is thread-enabled. As explained earlier, you can check thread build status with the tclsh oommf.tcl +platform command. If you want to force a non-threaded build of OOMMF, then edit the config/platforms/ file for your platform. In the section labeled LOCAL CONFIGURATION, you will find a line that looks like
# $config SetValue oommf_threads 0
Uncomment this line (i.e., remove the leading `#' character) to force a non-threaded build. Then run
tclsh oommf.tcl pimake distclean
tclsh oommf.tcl pimake
from the OOMMF root directory to create a fresh build.

You can use the tclsh oommf.tcl +platform command to see the default number of compute threads that will be run by the Oxs 3D solver programs oxsii and boxsi. You can modify the default by editing the oommf_thread_count value in the config/platforms/ file for your platform. You can override the default at run time by setting the environment variable OOMMF_THREADS, or by using the command line option -threads to oxsii and boxsi.

Some multi-processor machines have a non-uniform memory architecture (NUMA), which means that although each processor can access all of system memory, some parts of memory can be accessed faster than others. Typically this is accomplished by dividing the system memory and processors into ``nodes.'' Memory accesses within a node are faster than accesses between nodes, and depending on the architecture access latency and bandwidth may be different between different node pairs. Examples of machines with NUMA include some multi-processor AMD Opteron and Intel Xeon boxes.

Computer programs such as OOMMF can run on NUMA machines without making any special allowances for the memory architecture. However, a program that is written to take advantage of the faster local (intra-node) memory accesses can sometimes run significantly faster. OOMMF contains NUMA-aware code, but this code is highly operating system specific. At present, OOMMF can be built with NUMA support only on Linux (32- and 64-bit) systems. To do this, you must install the operating system NUMA support packages ``numactl'' and ``numactl-devel''. The names may vary somewhat between Linux distributions, but the first typically includes the executable numactl and the second includes the header file numa.h. Once the numactl package is installed, you can run the command

numactl --hardware
to get an overview of the memory architecture on your machine. If this shows you have only one node, then there is no advantage to making a NUMA-aware build of OOMMF.

The next step is to edit the config/platforms for your platform. For example, on a 64-bit Linux box this file is config/platforms/linux-x86_64.tcl. In the section labeled LOCAL CONFIGURATION, find the line

# $config SetValue use_numa 1
Edit this to remove the leading `#' character. Alternatively (and, actually, preferably), create a local subdirectory and make a local configuration file with the same platform name; e.g., config/platforms/local/linux-x86_64.tcl on a 64-bit Linux machine. Add the line
$config SetValue use_numa 1
to this file. (The advantage of using a config/platforms/local file is that you can make changes without modifying the original OOMMF source code, which makes it easier to port your local changes to future releases of OOMMF.) If this is done correctly, then the command `tclsh oommf.tcl +platform' will show that NUMA support is enabled. Then simply run `tclsh oommf.tcl pimake distclean' and `tclsh oommf.tcl pimake' from the OOMMF root directory to build a NUMA-aware version of OOMMF.

To activate the NUMA-aware code, you must specify the -numanodes option on the oxsii/boxsi command line, or set the the environment variable OOMMF_NUMANODES. Check the Oxs documention for details.


Managing OOMMF Platform Names

OOMMF software classifies computing platforms into different types using the scripts in the directory config/names relative to the root directory of the OOMMF distribution. Each type of computing platform is assigned a unique name. These names are used as directory names and in index and configuration files so that a single OOMMF installation may contain platform-dependent sections for many different types of computing platforms.

To learn what name OOMMF software uses to refer to your computing platform, run

tclsh oommf.tcl +platform
in the OOMMF root directory.

Changing the name OOMMF assigns to your platform

First, use pimake to build the target distclean to clear away any compiled executables built using the old platform name.

tclsh oommf.tcl pimake distclean
Then, to change the name OOMMF software uses to describe your platform from foo to bar, simply rename the file
config/names/foo.tcl to config/names/bar.tcl
and
config/platforms/foo.tcl to config/platforms/bar.tcl.
After renaming your platform type, you should recompile your executables using the new platform name.

Adding a new platform type

If oommf.tcl +platform reports the platform name unknown, then none of the scripts in config/names/ recognizes your platform type. As an example, to add the platform name foo to OOMMF's vocabulary of platform names, create the file config/names/foo.tcl. The simplest way to proceed is to copy an existing file in the directory config/names and edit it to recognize your platform.

The files in config/names include Tcl code like this:

  Oc_Config New _ \
    [string tolower [file rootname [file tail [info script]]]] {
      # In this block place the body of a Tcl proc which returns 1
      # if the machine on which the proc is executed is of the
      # platform type identified by this file, and which returns 0
      # otherwise.
      #
      # The usual Tcl language mechanism for discovering details 
      # about the machine on which the proc is running is to 
      # consult the global Tcl variable 'tcl_platform'.  See the
      # existing files for examples, or contact the OOMMF
      # developers for further assistance.
  }

After creating the new platform name file config/names/foo.tcl, you also need to create a new platform file config/platforms/foo.tcl. A reasonable starting point is to copy the file config/platforms/unknown.tcl for editing. Contact the OOMMF developers for assistance.

Please consider contributing your new platform recognition and configuration files to the OOMMF developers for inclusion in future releases of OOMMF software.

Resolving platform name conflicts

If the script oommf.tcl +platform reports ``Multiple platform names are compatible with your computer'', then there are multiple files in the directory config/names/ that return 1 when run on your computer. For each compatible platform name reported, edit the corresponding file in config/names/ so that only one of them returns 1. Experimenting using tclsh to probe the Tcl variable tcl_platform should assist you in this task. If that fails, you can explicitly assign a platform type corresponding to your computing platform by matching its hostname. For example, if your machine's host name is foo.bar.net:

  Oc_Config New _ \
    [string tolower [file rootname [file tail [info script]]]] {
      if {[string match foo.bar.net [info hostname]]} {
          return 1
      }
      # Continue with other tests...
  }

Contact the OOMMF developers if you need further assistance.


OOMMF Home next up previous Contents index

OOMMF Documentation Team
September 29, 2016