License: Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported license (CC BY-NC-ND 3.0)
When quoting this document, please refer to the following
DOI: 10.4230/OASIcs.WCET.2008.1666
URN: urn:nbn:de:0030-drops-16666
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2008/1666/
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Whitham, Jack ; Audsley, Neil

Traces as a Solution to Pessimism and Modeling Costs in WCET Analysis

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WhithamJack.Paper.1666.pdf (0.1 MB)

Abstract

WCET analysis models for superscalar out-of-order CPUs
generally need to be pessimistic in order to account for
a wide range of possible dynamic behavior. CPU hardware modifications
could be used to constrain operations to known execution paths
called traces, permitting exploitation of instruction
level parallelism with guaranteed
timing. Previous implementations of traces have used
microcode to constrain operations, but other possibilities
exist. A new implementation strategy (virtual
traces) is introduced here.

In this paper the benefits and costs of traces are discussed.
Advantages of traces include a reduction in pessimism in WCET analysis,
with the need to accurately model CPU internals removed. Disadvantages
of traces include a reduction of peak throughput of the CPU, a need
for deterministic memory and a potential increase in the complexity
of WCET models.

BibTeX - Entry

@InProceedings{whitham_et_al:OASIcs:2008:1666,
  author =	{Jack Whitham and Neil Audsley},
  title =	{{Traces as a Solution to Pessimism and Modeling Costs in WCET Analysis}},
  booktitle =	{8th International Workshop on Worst-Case Execution Time Analysis (WCET'08)},
  series =	{OpenAccess Series in Informatics (OASIcs)},
  ISBN =	{978-3-939897-10-1},
  ISSN =	{2190-6807},
  year =	{2008},
  volume =	{8},
  editor =	{Raimund Kirner},
  publisher =	{Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{http://drops.dagstuhl.de/opus/volltexte/2008/1666},
  URN =		{urn:nbn:de:0030-drops-16666},
  doi =		{10.4230/OASIcs.WCET.2008.1666},
  note =	{also published in print by Austrian Computer Society (OCG) with ISBN 978-3-85403-237-3},
  annote =	{Keywords: WCET superscalar cpu virtual traces}
}

Keywords: WCET superscalar cpu virtual traces
Collection: 8th International Workshop on Worst-Case Execution Time WCET Analysis (WCET'08)
Issue Date: 2008
Date of publication: 13.11.2008

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