000089714 001__ 89714
000089714 005__ 20210902121652.0
000089714 0247_ $$2doi$$a10.1371/journal.pone.0229980
000089714 0248_ $$2sideral$$a117493
000089714 037__ $$aART-2020-117493
000089714 041__ $$aeng
000089714 100__ $$0(orcid)0000-0002-4155-7687$$aPedro-Zapater, Alba
000089714 245__ $$aReducing the WCET and analysis time of systems with simple lockable instruction caches
000089714 260__ $$c2020
000089714 5060_ $$aAccess copy available to the general public$$fUnrestricted
000089714 5203_ $$aOne of the key challenges in real-time systems is the analysis of the memory hierarchy. Many Worst-Case Execution Time (WCET) analysis methods supporting an instruction cache are based on iterative or convergence algorithms, which are rather slow. Our goal in this paper is to reduce the WCET analysis time on systems with a simple lockable instruction cache, focusing on the Lock-MS method. First, we propose an algorithm to obtain a structure-based representation of the Control Flow Graph (CFG). It organizes the whole WCET problem as nested subproblems, which takes advantage of common branch-and-bound algorithms of Integer Linear Programming (ILP) solvers. Second, we add support for multiple locking points per task, each one with specific cache contents, instead of a given locked content for the whole task execution. Locking points are set heuristically before outer loops. Such simple heuristics adds no complexity, and reduces the WCET by taking profit of the temporal reuse found in loops. Since loops can be processed as isolated regions, the optimal contents to lock into cache for each region can be obtained, and the WCET analysis time is further reduced. With these two improvements, our WCET analysis is around 10 times faster than other approaches. Also, our results show that the WCET is reduced, and the hit ratio achieved for the lockable instruction cache is similar to that of a real execution with an LRU instruction cache. Finally, we analyze the WCET sensitivity to compiler optimization, showing for each benchmark the right choices and pointing out that O0 is always the worst option.
000089714 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/TIN2016-76635-C2-1-R$$9info:eu-repo/grantAgreement/ES/MEC/FPU14-02463$$9info:eu-repo/grantAgreement/ES/DGA/T58-17R
000089714 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000089714 590__ $$a3.24$$b2020
000089714 591__ $$aMULTIDISCIPLINARY SCIENCES$$b26 / 73 = 0.356$$c2020$$dQ2$$eT2
000089714 592__ $$a0.99$$b2020
000089714 593__ $$aMultidisciplinary$$c2020$$dQ1
000089714 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000089714 700__ $$0(orcid)0000-0003-1550-735X$$aSegarra, Juan$$uUniversidad de Zaragoza
000089714 700__ $$0(orcid)0000-0002-4031-5651$$aGran Tejero, Rubén$$uUniversidad de Zaragoza
000089714 700__ $$0(orcid)0000-0002-5976-1352$$aViñals, Víctor$$uUniversidad de Zaragoza
000089714 700__ $$aRodríguez, Clemente
000089714 7102_ $$15007$$2035$$aUniversidad de Zaragoza$$bDpto. Informát.Ingenie.Sistms.$$cÁrea Arquit.Tecnología Comput.
000089714 773__ $$g15, 3 (2020), e0229980 1-21$$pPLoS One$$tPloS one$$x1932-6203
000089714 8564_ $$s3595920$$uhttps://zaguan.unizar.es/record/89714/files/texto_completo.pdf$$yVersión publicada
000089714 8564_ $$s438087$$uhttps://zaguan.unizar.es/record/89714/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000089714 909CO $$ooai:zaguan.unizar.es:89714$$particulos$$pdriver
000089714 951__ $$a2021-09-02-09:07:26
000089714 980__ $$aARTICLE