Understanding the performance of mutual exclusion algorithms on modern multicore machines. Hugo Guiroux To cite this version: Hugo Guiroux. Understanding the performance of mutual exclusion algorithms on modern multicore machines.. Operating Systems [cs.OS]. Université Grenoble Alpes, 2018. English. tel-02133371 HAL Id: tel-02133371 https://tel.archives-ouvertes.fr/tel-02133371 Submitted on 18 May 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THÈSE Pour obtenir le grade de DOCTEUR DE LA COMMUNAUTÉ UNIVERSITÉ GRENOBLE ALPES Spécialité : Informatique Arrêté ministériel : 25 mai 2016 Présentée par Hugo GUIROUX Thèse dirigée par Vivien QUEMA, GRENOBLE INP et codirigée par Renaud LACHAIZE, UNIV. GRENOBLE ALPES préparée au sein du Laboratoire Laboratoire d'Informatique de Grenoble dans l'École Doctorale Mathématiques, Sciences et technologies de l'information, Informatique Comprendre la performance des algorithmes d'exclusion mutuelle sur les machines multicoeurs modernes Understanding the performance of mutual exclusion algorithms on modern multicore machines. Thèse soutenue publiquement le 17 décembre 2018, devant le jury composé de : Monsieur TIMOTHY HARRIS INGENIEUR, AMAZON A CAMBRIDGE - ROYAUME-UNI, Rapporteur Monsieur GAËL THOMAS PROFESSEUR, TELECOM SUD-PARIS, Rapporteur Monsieur ANDRZEJ DUDA PROFESSEUR, GRENOBLE INP, Président Monsieur PASCAL FELBER PROFESSEUR, UNIVERSITE DE NEUCHATEL - SUISSE, Examinateur Monsieur VIVIEN QUEMA PROFESSEUR, GRENOBLE INP, Directeur de thèse Monsieur RENAUD LACHAIZE MAITRE DE CONFERENCES, UNIVERSITE GRENOBLE ALPES, Examinateur We have arranged the whole system as a society of sequential processes whose harmonious cooperation is regulated by explicit mutual synchronization statements. — Edsger W. Dijkstra. To my wife, Justine. Acknowledgements First of all, I would like to thank the members of my Ph.D. thesis jury, Dr. Harris, Pr. Thomas, Pr. Duda and Pr. Felber, which have taken the time to examine my work and made meaningful comments and remarks before and during the defense. It was an honour for me to present my work in front of such a prestigious jury. I would also like to thank my two Ph.D. advisors, Renaud Lachaize and Vivien Quéma, for the long hours that we spent together discussing research ideas, profound scientific questions as well as non-scientific related topics. They both taught me to recognize what is a great research paper, to what standards my work should hold and how to make strong and interesting scientific work. They were here to support me during the difficult yet exciting experience that a Ph.D. can be. Doing this Ph.D. would have been less pleasurable without the member of the ERODS team, with which I had countless discussions. More precisely, I want to thank (in alphabetical order): Maha Alsayasneh, Fabienne Boyer, Thomas Calmant, Matthieu Caneill, Jeremie Decouchant, Amadou Diarra, Didier Donsez, Christopher Ferreira, Soulaimane Guedria, Olivier Gruber, Mohamad Jaafar, Vikas Jaiman, Vincent Lamotte, Vania Marangozova-Martin, Muriel Nguimtsa, Nicolas Palix, Noel de Palma, Albin Pe- tit, Ahmed El Rheddhane and Thomas Ropars. This thesis would not have happened without the financial support of the LIG and the University Grenoble Alpes. During this three years, I had the chance to do an internship inside the MLE team at Oracle Labs Zurich. This experience brought me a lot and opened my mind to other interesting research topics. First and foremost, I would like to thank Vasileios Trigonakis for being a friend, helping me and advising me when I needed it. Thanks to the MLE team and the Oracle Labs: Matthias Branter, Lucas Braun, Laurent Daynès, Bastian Hossbach, Alexander Ulrich and Alexander Schubert. A big shout out to all my friends that were here to support me during the three long years. Without you, I would not have done the Ph.D. that I did, even if you were not directly involved in my work. All the week-ends and holidays that we spent together helped me tremendously. A Ph.D. is a long journey, friends and family are the strong foundation that I needed. Thanks to Fairouz Azzoune, Carla Balbo, Perrine Blachon, Yoann Blein, Sandro Chionna, Jeanne Detroye, Aurélie Estermann, Clément Louis, Jennyfer Martinez, Simon Moura, Célia Muffato. Family is important: they provide a safe environment where anyone can talk openly about their feeling without being judged. I would like to thank both my family and my in-laws for their support iii Acknowledgements throughout the years. A special thank to my sister, who told me to not always take things too seriously and enjoy the life that I had, and to my father, who always gives me invaluable advices and who taught me to always be curious about everything. Finally, a final word for the person that is the most important in my life: Justine. Without you, I would not have done this Ph.D., and I would not have accomplished a lot of things that happened in my life. You were always here to support me and encourage me in everything that I tried to accomplish. You always believed in me, even when I was not. Thank you for everything that you did. Zurich, 05 January 2019 H. G. iv Preface This thesis presents the research conducted in the ERODS team at Laboratoire d’Inform- atique de Grenoble, to pursue a Ph.D. in Computer Science from the doctoral school “Mathématiques, Sciences et Technologies de l’Information, Informatique” of the Uni- versité Grenoble-Alpes. My research activities have been supervised by Vivien Quéma (ERODS / Grenoble INP) and Renaud Lachaize (ERODS / Université Grenoble Alpes). Some of the works presented in this thesis have been done in collaboration with members of the Distributed Programming Laboratory (LPD) of Ecole Polytechnique Fédérale de Lausanne (EPFL) [69]. This thesis studies and analyzes mutual exclusion lock algorithms on multicore appli- cations running on NUMA multicore machines. This work led to the following publications (authors are in alphabetical order): • Hugo Guiroux, Renaud Lachaize, and Vivien Quéma. “Multicore Locks: The Case Is Not Closed Yet”. 2016 USENIX Annual Technical Conference, USENIX ATC 2016, Denver, CO, USA, June 22-24, 2016. Ed. by Ajay Gulati and Hakim Weatherspoon. USENIX Association, 2016, pp. 649–662 • Rachid Guerraoui, Hugo Guiroux, Renaud Lachaize, Vivien Quéma, and Vasileios Trigonakis. “Lock – Unlock: Is That All? A Pragmatic Analysis of Locking in Software Systems”. ACM Transaction on Computer System (2018) (to appear) Grenoble, Summer 2018 H. G. v Abstract A plethora of optimized mutual exclusion lock algorithms have been designed over the past 25 years to mitigate performance bottlenecks related to critical sections and synchronization. Unfortunately, there is currently no broad study of the behavior of these optimized lock algorithms on realistic applications that consider different perfor- mance metrics, such as energy efficiency and tail latency. In this thesis, we perform a thorough and practical analysis, with the goal of providing software developers with enough information to achieve fast, scalable and energy-efficient synchronization in their systems. First, we provide a performance study of 28 state-of-the-art mutex lock algorithms, on 40 applications, and four different multicore machines. We not only consider throughput (traditionally the main performance metric), but also energy ef- ficiency and tail latency, which are becoming increasingly important. Second, we present an in-depth analysis in which we summarize our findings for all the studied applications. In particular, we describe nine different lock-related performance bottle- necks, and propose six guidelines helping software developers with their choice of a lock algorithm according to the different lock properties and the application character- istics. From our detailed analysis, we make a number of observations regarding locking algorithms and application behaviors, several of which have not been previously dis- covered: (i) applications not only stress the lock/unlock interface, but also the full locking API (e.g., trylocks, condition variables), (ii) the memory footprint of a lock can directly affect the application performance, (iii) for many applications, the interaction between locks and scheduling is an important application performance factor, (iv) lock tail latencies may or may not affect application tail latency, (v) no single lock is system- atically the best, (vi) choosing the best lock is difficult (as it depends on many factors such as the workload and the machine), and (vii) energy efficiency and throughput go hand in hand in the context of lock algorithms. These findings highlight that lock- ing involves more considerations than the simple “lock – unlock” interface and call for further research on designing low-memory footprint adaptive locks that fully and efficiently support the full lock interface, and consider all performance metrics. vii Résumé Une multitude d’algorithmes d’exclusion mutuelle ont été conçus au cours des vingt cinq dernières années, dans le but d’améliorer les performances liées à l’exécution