here - Stefan-Marr.de

8.1. Evaluation Strategy
posed evaluation measures its inherent overhead and its gains. It measures its
overhead on unenforced execution, and uses LRSTM and AmbientTalkST to
measure its performance benefit.
The evaluation is completed by measuring the absolute performance of
AST-OMOP and RoarVM+OMOP. While these absolute numbers do not contribute
to the evaluation goal, they are a relevant data points for the assessment
of whether the OMOP can be applied in its current form.
8.1.3. Virtual Machines
The evaluation uses the CogVM and the RoarVM. This section briefly lists the
basic information required to recreate the setup. Furthermore, it describes the
characteristics of the RoarVM variants used in the experiments.
CogVM The used CogVM (cf. Sec. 4.3) is the official and unmodified VM
for the Squeak and Pharo projects. It has been obtained from the continuous
integration server of the Pharo project. 11 It was compiled on Aug. 13th, 2012,
and identifies itself as a 6.0-pre release.
RoarVM The RoarVM used in these experiments is based on the official
sources, 12 but contains a number of customizations. In total, three variants
of the RoarVM without OMOP support are used. RoarVM (std) is the variant
that uses the standard settings of the VM and supports parallel execution. It is
compiled with Clang 3.0, 13 since Clang is the compiler used during development.
In order to assess whether the performance differences are significant
between Clang 3.0 and the standard compiler of OS X 10.6, i. e., the GNU
GCC 4.2, 14 the RoarVM (GCC 4.2) is included in the experiments. The only
difference with RoarVM (std) is the use of the GNU GCC 4.2 compiler. Independent
of the compiler, all RoarVM variants are compiled with maximum
optimizations, i. e., with the -O3 compiler flag.
Parallel Execution vs. Overhead Assessment For improved performance
and to expose the introduced overhead of the OMOP more clearly, this evaluation
uses RoarVM (opt), which is configured with non-standard settings.
11 https://ci.lille.inria.fr/pharo/view/Cog/job/Cog-VM/
12 https://github.com/smarr/RoarVM
13 http://clang.llvm.org/
14 To be precise, the compiler identification is: (GCC) 4.2.1 (Based on Apple Inc. build 5658)
(LLVM build 2336.1.00).
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