15 research outputs found
Automated prioritizing heuristics for parallel task graph scheduling in heterogeneous computing
International audienceHigh-performance computing (HPC) relies increasingly on heterogeneous hardware and especially on the combination of central and graphical processing units. The task-based method has demonstrated promising potential for parallelizing applications on such computing nodes. With this approach, the scheduling strategy becomes a critical layer that describes where and when the ready-tasks should be executed among the processing units. In this study, we describe a heuristic-based approach that assigns priorities to each task type. We rely on a fitness score for each task/worker combination for generating priorities and use these for configuring the Heteroprio scheduler automatically within the StarPU runtime system. We evaluate our methodâs theoretical performance on emulated executions and its real-case performance on multiple different HPC applications. We show that our approach is usually equivalent or faster than expert-defined priorities
Autovesk: Automatic vectorized code generation from unstructured static kernels using graph transformations
International audienceLeveraging the SIMD capability of modern CPU architectures is mandatory to take full advantage of their increased performance. To exploit this capability, binary executables must be vectorized, either manually by developers or automatically by a tool. For this reason, the compilation research community has developed several strategies for transforming scalar code into a vectorized implementation. However, most existing automatic vectorization techniques in modern compilers are designed for regular codes, leaving irregular applications with non-contiguous data access patterns at a disadvantage. In this paper, we present a new tool, Autovesk, that automatically generates vectorized code from scalar code, specifically targeting irregular data access patterns. We describe how our method transforms a graph of scalar instructions into a vectorized one, using different heuristics to reduce the number or cost of instructions. Finally, we demonstrate theeffectiveness of our approach on various computational kernels using Intel AVX-512 and ARM SVE. We compare the speedups of Autovesk vectorized code over GCC, Clang LLVM and Intel automatic vectorization optimizations. We achieve competitive results on linear kernels and up to 11x speedups on irregular kernels
Design of an Efficient Distributed Delivery Service for Group Key Agreement Protocols
International audienceEnd-to-end encrypted messaging applications such as Signal became widely popular thanks to their capability to ensure the confidentiality and integrity of online communication. While the highest security guarantees were long reserved to two-party communication, solutions for n-party communication remained either inefficient or less secure until the standardization of the MLS Protocol (Messaging Layer Security). This new protocol offers an efficient way to provide end-to-end secure communication with the same guarantees originally offered by the Signal Protocol for two-party communication. However, both solutions still rely on a centralized component for message delivery, called the Delivery Service in the MLS Protocol. The centralization of the Delivery Service makes it an ideal target for attackers and threatens the availability of any protocol relying on MLS. In order to overcome this issue, we propose the design of a fully distributed Delivery Service that allows clients to exchange protocol messages efficiently and without any intermediary. It uses a Probabilistic Reliable-Broadcast mechanism to efficiently deliver messages and the Cascade Consensus Protocol to handle messages requiring an agreement. Our solution strengthens the availability of the MLS Protocol without compromising its security
Design of an Efficient Distributed Delivery Service for Group Key Agreement Protocols
International audienceEnd-to-end encrypted messaging applications such as Signal became widely popular thanks to their capability to ensure the confidentiality and integrity of online communication. While the highest security guarantees were long reserved to two-party communication, solutions for n-party communication remained either inefficient or less secure until the standardization of the MLS Protocol (Messaging Layer Security). This new protocol offers an efficient way to provide end-to-end secure communication with the same guarantees originally offered by the Signal Protocol for two-party communication. However, both solutions still rely on a centralized component for message delivery, called the Delivery Service in the MLS Protocol. The centralization of the Delivery Service makes it an ideal target for attackers and threatens the availability of any protocol relying on MLS. In order to overcome this issue, we propose the design of a fully distributed Delivery Service that allows clients to exchange protocol messages efficiently and without any intermediary. It uses a Probabilistic Reliable-Broadcast mechanism to efficiently deliver messages and the Cascade Consensus Protocol to handle messages requiring an agreement. Our solution strengthens the availability of the MLS Protocol without compromising its security
Design of an Efficient Distributed Delivery Service for Group Key Agreement Protocols
International audienceEnd-to-end encrypted messaging applications such as Signal became widely popular thanks to their capability to ensure the confidentiality and integrity of online communication. While the highest security guarantees were long reserved to two-party communication, solutions for n-party communication remained either inefficient or less secure until the standardization of the MLS Protocol (Messaging Layer Security). This new protocol offers an efficient way to provide end-to-end secure communication with the same guarantees originally offered by the Signal Protocol for two-party communication. However, both solutions still rely on a centralized component for message delivery, called the Delivery Service in the MLS Protocol. The centralization of the Delivery Service makes it an ideal target for attackers and threatens the availability of any protocol relying on MLS. In order to overcome this issue, we propose the design of a fully distributed Delivery Service that allows clients to exchange protocol messages efficiently and without any intermediary. It uses a Probabilistic Reliable-Broadcast mechanism to efficiently deliver messages and the Cascade Consensus Protocol to handle messages requiring an agreement. Our solution strengthens the availability of the MLS Protocol without compromising its security
Le contrÎle de l'identité à travers les ùges
Garnier Ludovic, Lebas Fabien, Leger Claire, Lemoine Raphaëlle, Marcilly Matthieu, Mellal Fatiha, Paillat Xavier, Vercelonne Samuel, Verge Mélanie. Le contrÎle de l'identité à travers les ùges. In: Revue juridique de l'Ouest, 2012-3. pp. 343-362
Expertise prĂ©alable Ă la crĂ©ation dâun tableau de maladie professionnelle ou Ă lâĂ©laboration derecommandations aux comitĂ©s rĂ©gionaux de reconnaissance des maladies professionnelles - LeucĂ©mies myĂ©loĂŻdes en lien avec lâexposition au formaldĂ©hyde
Citation suggĂ©rĂ©e : Anses. (2023). Expertise prĂ©alable Ă la crĂ©ation d'un tableau de maladie professionnelle ou Ă lâĂ©laboration de recommandations aux comitĂ©s rĂ©gionaux de reconnaissance des maladies professionnelles â LeucĂ©mies myĂ©loĂŻdes en lien avec lâexposition au formaldĂ©hyde. (Saisine 2021-SA-0031). Maisons-Alfort : Anses, 289 p.Depuis 2004, le formaldĂ©hyde est classĂ© par le Centre international de recherche sur le cancer(CIRC) comme substance « cancĂ©rogĂšne avĂ©rĂ©e pour lâhumain » (groupe 1) pour le nasopharynx (IARC, 2006). La monographie sur le formaldĂ©hyde actualisĂ©e en 2009 indique que des preuves suffisantes sont maintenant disponibles pour dĂ©montrer le lien entre lâexposition au formaldĂ©hyde et les leucĂ©mies dont la leucĂ©mie myĂ©loĂŻde (IARC, 2012). Dans cette monographie, une association positive a Ă©tĂ© observĂ©e entre l'exposition au formaldĂ©hyde et le cancer des fosses nasales et des sinus de la face, sans pouvoir conclure sur le lien de causalitĂ©.Au niveau europĂ©en et Ă la suite dâune proposition de classification prĂ©parĂ©e par lâAnses etenvoyĂ©e Ă lâAgence europĂ©enne des substances chimiques (ECHA) en 2011, la classificationharmonisĂ©e du formaldĂ©hyde a Ă©voluĂ©, dans le cadre du rĂšglement (UE) n° 605/2014 de laCommission du 5 juin 2014, de la catĂ©gorie « cancĂ©rogĂšne de catĂ©gorie 2 - susceptible deprovoquer le cancer » vers la catĂ©gorie « cancĂ©rogĂšne de catĂ©gorie 1B - peut provoquer lecancer » et « mutagĂšne de catĂ©gorie 2 - susceptible d'induire des anomalies gĂ©nĂ©tiques », surla base des tumeurs du naso-pharynx.En France, les ministĂšres chargĂ©s du travail et de lâagriculture ont publiĂ© un arrĂȘtĂ© en juillet2006 classant les « travaux exposant au formaldĂ©hyde » dans la liste des activitĂ©s impliquantdes substances, prĂ©parations et procĂ©dĂ©s cancĂ©rogĂšnes, au sens du Code du travail. LâentrĂ©een vigueur de cet arrĂȘtĂ© est effective depuis janvier 2007.Concernant la reconnaissance des maladies professionnelles (MP), quatre tableaux de maladies professionnelles (TMP) ont Ă©tĂ© crĂ©Ă©s aux rĂ©gimes gĂ©nĂ©ral (RG) et agricole (RA). Les tableaux 43 RG (crĂ©Ă© en 1963) et 28 RA (crĂ©Ă© en 1955) portent sur les affections (dermites, eczĂ©ma, rhinite, asthme) provoquĂ©es par le formaldĂ©hyde, et les tableaux 43 bis RG (crĂ©Ă© en 2009) et 28 bis RA (crĂ©Ă© en 2012) sur le cancer du nasopharynx.Compte tenu des Ă©volutions des connaissances relatives aux pathologies liĂ©es aux expositionsau formaldĂ©hyde, la Direction gĂ©nĂ©rale du travail, la Direction de la sĂ©curitĂ© sociale et la Direction des affaires financiĂšres, sociales et logistiques ont saisi lâAnses le 23 fĂ©vrier 2021 pour rĂ©aliser un travail dâexpertise prĂ©alable Ă la crĂ©ation de tableaux en lien avec les expositions professionnelles au formaldĂ©hyde.Cette saisine fait mention de plusieurs maladies en lien avec lâexposition au formaldĂ©hyde : les leucĂ©mies et particuliĂšrement les leucĂ©mies myĂ©loĂŻdes, le cancer des fosses nasales et des sinus de la face ainsi que les pathologies rĂ©sultant de sensibilisation et dâeffets locaux (irritation, corrosion). Il est Ă©galement demandĂ© une mise Ă jour des TMP 43 et 43 bis du RG, 28 et 28 bis du RA, sâil existe des Ă©lĂ©ments nouveaux susceptibles de faire Ă©voluer ces tableaux.Cette expertise permettra aux commissions de maladies professionnelles et Ă lâĂtat de mettre Ă jour, le cas Ă©chĂ©ant, les modalitĂ©s de la reconnaissance des maladies professionnelles liĂ©es au formaldĂ©hyde, tant pour le rĂ©gime agricole que pour le rĂ©gime gĂ©nĂ©ral, ou de formuler desrecommandations aux comitĂ©s rĂ©gionaux de reconnaissance des maladies professionnelles(CRRMP)