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The RubyCache (CacheMemory) latency parameter is only used for top-level caches instantiated for Ruby coherence protocols. However, the top-level cache hit latency is assessed by the Sequencer as accesses flow through to the cache hierarchy. Further, protocol state machines should be enforcing these cache hit latencies, but RubyCaches do not expose their latency to any existng state machines through the SLICC/C++ interface. Thus, the RubyCache latency parameter is superfluous for all caches. This is confusing for users. As a step toward pushing L0/L1 cache hit latency into the top-level cache controllers, move their latencies out of the RubyCache declarations and over to their Sequencers. Eventually, these Sequencer parameters should be exposed as parameters to the top-level cache controllers, which should assess the latency. NOTE: Assessing these latencies in the cache controllers will require modifying each to eliminate instantaneous Ruby hit callbacks in transitions that finish accesses, which is likely a large undertaking.
This is the gem5 simulator. The main website can be found at http://www.gem5.org A good starting point is http://www.gem5.org/Introduction, and for more information about building the simulator and getting started please see http://www.gem5.org/Documentation and http://www.gem5.org/Tutorials. To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/Dependencies for more details concerning the minimum versions of the aforementioned tools. Once you have all dependencies resolved, type 'scons build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS, POWER, SPARC, or X86. This will build an optimized version of the gem5 binary (gem5.opt) for the the specified architecture. See http://www.gem5.org/Build_System for more details and options. With the simulator built, have a look at http://www.gem5.org/Running_gem5 for more information on how to use gem5. The basic source release includes these subdirectories: - configs: example simulation configuration scripts - ext: less-common external packages needed to build gem5 - src: source code of the gem5 simulator - system: source for some optional system software for simulated systems - tests: regression tests - util: useful utility programs and files To run full-system simulations, you will need compiled system firmware (console and PALcode for Alpha), kernel binaries and one or more disk images. Please see the gem5 download page for these items at http://www.gem5.org/Download If you have questions, please send mail to gem5-users@gem5.org Enjoy using gem5 and please share your modifications and extensions.