6a4b2bb096
The AMD specific HSA signal contains start/end timestamps for dispatch packet completion signals. These are current always zero. These timestamp values are used for profiling in the ROCr runtime. Unfortunately, the GpuAgent::TranslateTime method in ROCr does not check for zero values before dividing, causing applications that use profiling to crash with SIGFPE. Profiling is used via hipEvents in the HACC application, so these should be supported in gem5. In order to handle writing the timestamp values, we need to DMA the values to memory before writing the completion signal. This changes the flow of the async completion signal write to be (1) read mailbox pointer (2) if valid, write the mailbox data, other skip to 4 (3) write mailbox data if pointer is valid (4) write timestamp values (5) write completion signal. The application will process the timestamp data as soon as the completion signal is received, so we need to ordering to ensure the DMA for timestamps was completed. HACC now runs to completion on GPUFS and has the same output was hardware. Change-Id: I09877cdff901d1402140f2c3bafea7605fa6554e
The gem5 Simulator
This is the repository for the gem5 simulator. It contains the full source code for the simulator and all tests and regressions.
The gem5 simulator is a modular platform for computer-system architecture research, encompassing system-level architecture as well as processor microarchitecture. It is primarily used to evaluate new hardware designs, system software changes, and compile-time and run-time system optimizations.
The main website can be found at http://www.gem5.org.
Testing status
Note: These regard tests run on the develop branch of gem5: https://github.com/gem5/gem5/tree/develop.
Getting started
A good starting point is http://www.gem5.org/about, and for more information about building the simulator and getting started please see http://www.gem5.org/documentation and http://www.gem5.org/documentation/learning_gem5/introduction.
Building gem5
To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/documentation/general_docs/building for more details concerning the minimum versions of these tools.
Once you have all dependencies resolved, execute
scons build/ALL/gem5.opt to build an optimized version of the gem5 binary
(gem5.opt) containing all gem5 ISAs. If you only wish to compile gem5 to
include a single ISA, you can replace ALL with the name of the ISA. Valid
options include ARM, NULL, MIPS, POWER, SPARC, and X86 The complete
list of options can be found in the build_opts directory.
See https://www.gem5.org/documentation/general_docs/building for more information on building gem5.
The Source Tree
The main source tree includes these subdirectories:
- build_opts: pre-made default configurations for gem5
- build_tools: tools used internally by gem5's build process.
- configs: example simulation configuration scripts
- ext: less-common external packages needed to build gem5
- include: include files for use in other programs
- site_scons: modular components of the build system
- src: source code of the gem5 simulator. The C++ source, Python wrappers, and Python standard library are found in this directory.
- system: source for some optional system software for simulated systems
- tests: regression tests
- util: useful utility programs and files
gem5 Resources
To run full-system simulations, you may need compiled system firmware, kernel binaries and one or more disk images, depending on gem5's configuration and what type of workload you're trying to run. Many of these resources can be obtained from https://resources.gem5.org.
More information on gem5 Resources can be found at https://www.gem5.org/documentation/general_docs/gem5_resources/.
Getting Help, Reporting bugs, and Requesting Features
We provide a variety of channels for users and developers to get help, report bugs, requests features, or engage in community discussions. Below are a few of the most common we recommend using.
- GitHub Discussions: A GitHub Discussions page. This can be used to start discussions or ask questions. Available at https://github.com/orgs/gem5/discussions.
- GitHub Issues: A GitHub Issues page for reporting bugs or requesting features. Available at https://github.com/gem5/gem5/issues.
- Jira Issue Tracker: A Jira Issue Tracker for reporting bugs or requesting features. Available at https://gem5.atlassian.net/.
- Slack: A Slack server with a variety of channels for the gem5 community to engage in a variety of discussions. Please visit https://www.gem5.org/join-slack to join.
- gem5-users@gem5.org: A mailing list for users of gem5 to ask questions or start discussions. To join the mailing list please visit https://www.gem5.org/mailing_lists.
- gem5-dev@gem5.org: A mailing list for developers of gem5 to ask questions or start discussions. To join the mailing list please visit https://www.gem5.org/mailing_lists.
Contributing to gem5
We hope you enjoy using gem5. When appropriate we advise charing your contributions to the project. https://www.gem5.org/contributing can help you get started. Additional information can be found in the CONTRIBUTING.md file.