GEOPM - Global Extensible Open Power Manager
WEB PAGES
https://geopm.github.io
https://geopm.github.io/man/geopm.7.html
https://geopm.slack.com
SUMMARY
The Global Extensible Open Power Manager (GEOPM) is a framework for exploring power and energy optimizations targeting high performance computing.
With GEOPM you can:
- Interact with hardware settings using a platform-agnostic interface
- Profile applications to study their power and energy behavior
- Automatically detect MPI and OpenMP phases in an application
- Optimize MPI applications to improve energy efficiency or reduce the effects of work imbalance, system jitter, and manufacturing variation through built-in control algorithms
- Develop your own runtime control algorithms through the extensible plugin architecture
DESCRIPTION
The GEOPM package provides many built-in features. A simple use case is reading hardware counters and setting hardware controls with platform independant syntax using a command line tool on a particular compute node. An advanced use case is dynamically coordinating hardware settings across all compute nodes used by an application in response to the application's behavior and requests from the resource manager. The dynamic coordination is implemented as a hierarchical control system for scalable communication and decentralized control. The hierarchical control system can optimize for various objective functions including maximizing global application performance within a power bound or minimizing energy consumption with marginal degradation of application performance. The root of the control hierarchy tree can communicate with the system resource manager to extend the hierarchy above the individual MPI application and enable the management of system power resources for multiple MPI jobs and multiple users by the system resource manager.
The GEOPM package provides two libraries: libgeopm for use with MPI applications, and libgeopmpolicy for use with applications that do not link to MPI. There are several command line tools included in GEOPM which have dedicated manual pages. The geopmlaunch(1) command line tool is used to launch an MPI application while enabling the GEOPM runtime to create a GEOPM Controller thread on each compute node. The Controller loads plugins and executes the Agent algorithm to control the compute application. The geopmlaunch(1) command is part of the geopmpy python package that is included in the GEOPM installation. See the GEOPM overview man page for further documentation and links: geopm(7).
The GEOPM runtime is extended through three plugin classes: Agent, IOGroup, and Comm. New implementations of these classes can be dynamically loaded at runtime by the GEOPM Controller. The Agent class defines which data are collected, how control decisions are made, and what messages are communicated between Agents in the tree hierarchy. The reading of data and writing of controls from within a compute node is abstracted from the Agent through the PlatformIO interface. This interface provides access to the IOGroup implementations that provide a variety of signals and controls. IOGroup plugins can be developed independently of the Agents to extend the read and write capabilities provided by GEOPM. The PlatformIO abstraction enables Agent implementations to be ported to different hardware platforms without modification. Messaging between Agents running on different compute nodes is encapsulated in the Comm class. New implementations of the Comm class make it possible to port inter-node communication used by the GEOPM runtime to different underlying communication protocols and hardware without modifying the Agent implementations.
The libgeopm library can be called directly or indirectly within MPI applications to enable application feedback for informing the control decisions. The indirect calls are facilitated by GEOPM's integration with MPI and OpenMP through their profiling decorators, and the direct calls are made through the geopm_prof_c(3) or geopm_fortran(3) interfaces. Marking up a compute application with profiling information through these interfaces can enable better integration of the GEOPM runtime with the compute application and more precise control.
TRAVIS CI
The GEOPM public GitHub project has been integrated with Travis continuous integration.
http://travis-ci.org/geopm/geopm
All pull requests will be built and tested automatically by Travis.
INSTALL
The OpenHPC project provides the most robust way to install GEOPM.
The GEOPM project was first packaged with OpenHPC version 1.3.6. The OpenHPC install guide contains documentation on how to install GEOPM and its dependencies and can be found on the OpenHPC download page.
The OpenHPC packages are distributed from the OpenHPC OBS build server.
The OpenHPC project packages all of the dependencies required by GEOPM that are not part of a standard Linux distribution. This includes the msr-safe kernel driver and MSR save/restore functionality built into the Slurm resource manager to enable robust reset of hardware controls when returning compute nodes to the general pool available to other users.
PYTHON INSTALL
The GEOPM python tools are packaged in the RPMs described above, but the latest release is also available from PyPI as the geopmpy package. For example, to install the geopmpy package into your home directory, run the following command:
python -m pip install --user geopmpy
You may wish to install the latest development version of GEOPM as many of the features arriving in GEOPM v2.0 are not yet available from PyPI. To install the latest development version of the geopmpy package directly from GitHub, run the following command:
python -m pip install --user "git+https://github.com/geopm/geopm.git@dev#egg=geopmpy&subdirectory=scripts"
Note these commands only install the GEOPM Python tools and do not install the binaries required by the GEOPM runtime. Without these binary files only the following modules will load successfully:
geopmpy.io geopmpy.launcher geopmpy.plotter geopmpy.update_report
All other modules rely on the output of the GEOPM build (namely libgeopmpolicy.so) being present and available in LD_LIBRARY_PATH or similar.
Anaconda Usage
To create an Anaconda environment that contains the geopmpy package, run the following commands:
conda init conda activate # base env conda create --name geopm conda activate --stack geopm conda install git pip # To ensure usage of the env's pip and not system pip python -m pip install "git+https://github.com/geopm/geopm.git@dev#egg=geopmpy&subdirectory=scripts"
BUILD REQUIREMENTS
In order to build the GEOPM package from source, the below requirements must be met. The user can opt out of the features enabled by any of these requirements by providing the appropriate disable flag to the configure command line.
The GEOPM package requires a compiler that supports the MPI 2.2 and C++11 standards. These requirements can be met by using GCC version 4.7 or greater and installing the openmpi-devel package version 1.7 or greater on RHEL and SLES Linux, and libopenmpi-dev on Ubuntu. Documentation creation including man pages further requires the rubygems and ruby-devel package on RHEL and SLES, or ruby and ruby-dev on Ubuntu.
RHEL:
yum install openmpi-devel elfutils-libelf-devel ruby-devel rubygems
SUSE:
zypper install openmpi-devel elfutils-libelf-devel ruby-devel rubygems
UBUNTU (as of 18.04.3 LTS):
apt install libtool automake libopenmpi-dev build-essential gfortran \
libelf-dev ruby ruby-dev python libsqlite3-dev
Requirements that can be avoided by removing features with configure option:
- MPI compiler: –disable-mpi
- A Fortran compiler: –disable-fortran
- The elfutils library: –disable-ompt
Alternatively these can be installed from source, and an alternate MPI implementation to OpenMPI can be selected (e.g. the Intel distribution of MPI). See
./configure --help
for details on how to use non-standard install locations for build requirements through the
./configure --with-<feature>
options.
BUILD INSTRUCTIONS
The source code can be rebuilt from the source RPMs available from OpenHPC. To build from the git repository follow the instructions below.
If building with the Intel toolchain the following environment variables must be set prior to running configure:
export CC=icc export CXX=icpc export FC=ifort export F77=ifort export MPICC=mpiicc export MPICXX=mpiicpc export MPIFC=mpiifort export MPIF77=mpiifort
To build all targets and install it in a "build/geopm" subdirectory of your home directory run the following commands:
./autogen.sh ./configure --prefix=$HOME/build/geopm make make install
An RPM can be created on a RHEL or SUSE system with the
make rpm
target. Note that the –with-mpi-bin option may be required to inform configure about the location of the MPI compiler wrappers. The following command may be sufficient to determine the location:
dirname $(find /usr -name mpicc)
To build in an environment without support for OpenMP (i.e. clang on Mac OS X) use the
./configure --disable-openmp
option. The
./configure --disable-mpi
option can be used to build only targets which do not require MPI. By default MPI targets are built.
RUN REQUIREMENTS
We are targeting SLES12 and RHEL7 distributions for functional runtime support. There is a single runtime requirement that can be obtained from these distributions for the OpenMPI implementation of MPI. To install, follow the instructions below for your Linux distribution.
RHEL:
yum install openmpi
SUSE:
zypper install openmpi
Alternatively the MPI requirement can be met by using OpenHPC packages.
BIOS Configuration
If power governing or power balancing is the intended use case for GEOPM deployment then there is an additional dependency on the BIOS being configured to support RAPL control. To check for BIOS support, execute the following on a compute node: ./tutorial/admin/00_test_prereqs.sh
If the script output contains: WARNING: The lock bit for the PKG_POWER_LIMIT MSR is set. The power_balancer and power_governor agents will not function properly until this is cleared.
Please enable RAPL in your BIOS and if such an option doesn't exist please contact your BIOS vendor to obtain a RAPL supported BIOS.
For additional information, please contact the GEOPM team.
USER ENVIRONMENT
The libraries, binaries and python tools will not be installed into the standard system paths if GEOPM is built from source and configured with the --prefix option. In this case, it is required that the user augment their environment to specify the installed location. If the configure option is specified as above:
GEOPM_PREFIX=$HOME/build/geopm ./configure --prefix=$GEOPM_PREFIX
then the following modifications to the user's environment should be made prior to running any GEOPM tools:
export LD_LIBRARY_PATH=$GEOPM_PREFIX/lib:$LD_LIBRARY_PATH export PATH=$GEOPM_PREFIX/bin:$PATH export PYTHONPATH=$(ls -d $GEOPM_PREFIX/lib/python*/site-packages | tail -n1):$PYTHONPATH
Use a PYTHONPATH that points to the site-packages created by the geopm build. The version created is for whichever version of python 3 was used in the configure step. If a different version of python is desired, override the default with the –with-python option in the configure script.
SYSTEMD CONFIGURATION
In order for GEOPM to properly use shared memory to communicate between the Controller and the application, it may be necessary to alter the configuration for systemd. The default behavior of systemd is to clean-up all inter-process communication for non-system users. This causes issues with GEOPM's initialization routines for shared memory. This can be disabled by ensuring that RemoveIPC=no is set in /etc/systemd/logind.conf. Most Linux distributions change the default setting to disable this behavior. More information can be found here.
MSR DRIVER
The msr-safe kernel driver must be loaded at runtime to support user-level read and write of the model specific registers (MSRs) configured by the allowed list. The msr-safe kernel driver is distributed with OpenHPC and can be installed using the RPMs distributed there (see INSTALL section above).
The source code for the driver can be found here at the link below.
Alternately, you can run GEOPM as root with the standard msr driver loaded:
modprobe msr
LINUX POWER MANAGEMENT
Note that other Linux mechanisms for power management can interfere with GEOPM, and these must be disabled. We suggest disabling the intel_pstate kernel driver by modifying the kernel command line through grub2 or the boot loader on your system by adding:
"intel_pstate=disable"
The cpufreq driver will be enabled when the intel_pstate driver is disabled. The cpufreq driver has several modes controlled by the scaling_governor sysfs entry. When the performance mode is selected, the driver will not interfere with GEOPM. For SLURM based systems the GEOPM launch wrappers will attempt to set the scaling governor to "performance". This alleviates the need to manually set the governor. Older versions of SLURM require the desired governors to be explicitly listed in /etc/slurm.conf. In particular, SLURM 15.x requires the following option:
CpuFreqGovernors=OnDemand,Performance
More information on the slurm.conf file can be found here. Non-SLURM systems must still set the scaling governor through some other mechanism to ensure proper GEOPM behavior. The following command will set the governor to performance:
echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
See kernel documentation here for more information.
GEOPM APPLICATION LAUNCH WRAPPER
The GEOPM package installs the command, "geopmlaunch". This is a wrapper for the MPI launch commands like "srun", "aprun", and "mpiexec" where the wrapper script enables the GEOPM runtime. The "geopmlaunch" command supports exactly the same command line interface as the underlying launch command, but the wrapper extends the interface with GEOPM specific options. The "geopmlaunch" application launches the primary compute application and the GEOPM control thread on each compute node and manages the CPU affinity requirements for all processes. The wrapper is documented in the geopmlaunch(1) man page.
There are several underlying MPI application launchers that "geopmlaunch" wrapper supports. See the geopmlaunch(1) man page for information on available launchers and how to select them. If the launch mechanism for your system is not supported, then affinity requirements must be enforced by the user and all options to the GEOPM runtime must be passed through environment variables. Please consult the geopm(7) man page for documentation of the environment variables used by the GEOPM runtime that are otherwise controlled by the wrapper script.
CPU AFFINITY REQUIREMENTS
The GEOPM runtime requires that each MPI process of the application under control is affinitized to distinct CPUs. This is a strict requirement for the runtime and must be enforced by the MPI launch command. When using the geopmlaunch wrapper described in the previous section, these affinity requirements are handled by geopmlaunch unless the –geopm-affinity-disable command line option is provided (see geopmlaunch(1)).
While the GEOPM control thread connects to the application it will automatically affinitize itself to the highest indexed core not used by the application if the application is not affinitized to a CPU on every core. In the case were the application is utilizing all cores of the system, the GEOPM control thread will be pinned to the highest logical CPU.
There are many ways to launch an MPI application, and there is no single uniform way of enforcing MPI rank CPU affinities across different job launch mechanisms. Additionally, OpenMP runtimes, which are associated with the compiler choice, have different mechanisms for affinitizing OpenMP threads within CPUs available to each MPI process. To complicate things further the GEOPM control thread can be launched as an application thread or a process that may be part of the primary MPI application or a completely separate MPI application. For these reasons it is difficult to document how to correctly affinitize processes in all configurations. Please refer to your site documentation about CPU affinity for the best solution on the system you are using and consider extending the geopmlaunch wrapper to support your system configuration (please see the CONTRIBUTING.md file for information about how to share these implementation with the community).
TESTING
From within the source code directory, unit tests can be executed with the "make check" target. The unit tests can be built without executing them with the "make checkprogs" target. A typical parallel build and test cyle is executed with the following commands:
make -j make checkprogs -j make check
The unit tests can be executed on any development system, including VMs and containers, that meets the BUILD REQUIREMENTS section above.
The integration tests are located in the "integration/test" directory. These tests require a system meeting all of the requirements discussed in the RUN REQUIREMENTS section above. The following script can be used to compile the GEOPM source, install into a specified location and execute the integration scripts in a work directory.
##### USER SPECIFIC #####
# Set the location of the GEOPM source tree
export GEOPM_SOURCE=${HOME}/Git/geopm
# Set the install prefix for the geopm build
export GEOPM_INSTALL=${HOME}/build/geopm
# Set a place to locate the output of the tests
export GEOPM_WORKDIR=${HOME}/geopm_test
##### ALL USERS #####
# Script defines bash functions to build and install GEOPM
source $GEOPM_SOURCE/integration/apps/build_func.sh
# Execute out-of-place build and install using build function
install_geopm
# Set up run environment to use installed GEOPM
source $GEOPM_SOURCE/integration/config/run_env.sh
# Create a directory for output
mkdir -p $GEOPM_WORKDIR
cd $GEOPM_WORKDIR
# Run the integration tests
python3 $GEOPM_SOURCE/integration/test
These integration tests are based on pyunit and leverage the geopmpy python package to validate the runtime. Please report failures of these tests as issues.
Note that if the GEOPM_SKIP_COMPILER_CHECK environment variable is set when install_geopm is called, then the check to verify that the Intel compilers are used will be bypassed. This can be useful for performing builds with the GNU toolchain.
RESOURCE MANAGER INTEGRATION
The GEOPM package can be integrated with a compute cluster resource manager by modifying the resource manager daemon running on the cluster compute nodes. An example of integration with the SLURM resource manager via a SPANK plugin can be found here:
https://github.com/geopm/geopm-slurm
and the implementation reflects what is documented below.
Integration is achieved by modifying the daemon to make two libgeopmpolicy.so function calls prior to releasing resources to the user (prologue), and one call after the resources have been reclaimed from the user (epilogue). In the prologue, the resource manager compute node daemon calls:
geopm_pio_save_control()
which records into memory the value of all controls that can be written through GEOPM (see geopm_pio_c(3)). The second call made in the prologue is:
geopm_agent_enforce_policy()
and this call (see geopm_agent_c(3)) enforces the configured policy such as a power cap or a limit on CPU frequency by a one time adjustment of hardware settings. In the epilogue, the resource manager calls:
geopm_pio_restore_control()
which will set all GEOPM platform controls back to the values read in the prologue.
The configuration of the policy enforced in the prologue is controlled by the two files:
/etc/geopm/environment-default.json /etc/geopm/environment-override.json
which are JSON objects mapping GEOPM environment variable strings to string values. The default configuration file controls values used when a GEOPM variable is not set in the calling environment. The override configuration file enforces values for GEOPM variables regardless of what is specified in the calling environment. The list of all GEOPM environment variables can be found in the geopm(7) man page. The two GEOPM environment variables used by geopm_agent_enforce_policy() are "GEOPM_AGENT" and "GEOPM_POLICY". Note that it is expected that /etc is mounted on a node-local file system, so the geopm configuration files are typically part of the compute node boot image. Also note that the "GEOPM_POLICY" value specifies a path to another JSON file which may be located on a shared file system, and this second file controls the values enforced (e.g. power cap value in Watts, or CPU frequency value in Hz).
When configuring a cluster to use GEOPM as the site-wide power management solution, it is expected that one agent algorithm with one policy will be applied to all compute nodes within a queue partition. The system administrator selects the agent based on the site requirements. If the site requires that the average CPU power draw per compute node remains under a cap across the system, then they would choose the power_balancer agent (see geopm_agent_power_balancer(7)). If saving as much energy as possible with a limited impact on performance is the site requirement, then the energy_efficient agent would be selected (see geopm_agent_energy_efficient(7)). If the site would like to restrict applications to run below a particular CPU frequency unless they are executing a high priority optimized subroutine that has been granted permission by the site administration to run at an elevated CPU frequency, they would choose the frequency_map agent (see geopm_agent_frequency_map(7)). There is also the option for a site specific custom agent plugin to be deployed. In all of these use cases, calling geopm_agent_enforce_policy() prior to releasing compute node resources to the end user will enforce static limits to power or CPU frequency, and these will impact all user applications. In order to leverage the dynamic runtime features of GEOPM, the user must opt-in by launching their MPI application with the geopmlaunch(1) command line tool.
The following example shows how a system administrator would configure a system to use the power_balancer agent. This use case will enforce a static power limit for applications which do not use geopmlaunch(), and will optimize power limits to balance performance when geopmlaunch() is used. First, the system administrator creates the following JSON object in the boot image of the compute node in the path "/etc/geopm/environment-override.json":
{"GEOPM_AGENT": "power_balancer",
"GEOPM_POLICY": "/shared_fs/config/geopm_power_balancer.json"}
Note that the "POWER_PACKAGE_LIMIT_TOTAL" value controlling the limit is specified in a secondary JSON file "geopm_power_balancer.json" that may be located on a shared file system and can be created with the geopmagent(1) command line tool. Locating the policy file on the shared file system enables the limit to be modified without changing the compute node boot image. Changing the policy value will impact all subsequently launched GEOPM processes, but it will not change the behavior of already running GEOPM control processes.
STATUS
This software is production quality as of version 1.0. We will be enforcing semantic versioning for all releases following version 1.0. We are very interested in feedback from the community. Refer to the ChangeLog a high level history of changes in each release. See github issues page for information about ongoing work and please provide feedback by opening issues. Test coverage by unit tests is lacking for some files and will continue to be improved. The line coverage results from gcov as reported by gcovr for the latest release can be found here
Some new features of GEOPM are still under development, and their interfaces may change before they are included in official releases. To enable these features in the GEOPM install location, configure GEOPM with the --enable-beta configure flag. The features currently considered unfinalized are the endpoint interface, the geopmendpoint application, and the geopmplotter application.
DISCLAIMER
SEE COPYING FILE FOR LICENSE INFORMATION.
LAST UPDATE
2020 September 25
Christopher Cantalupo christopher.m.cantalupo@intel.com
Diana Guttman diana.r.guttman@intel.com
ACKNOWLEDGMENTS
Development of the GEOPM software package has been partially funded through contract B609815 with Argonne National Laboratory.
