A Compilation Flow for Parametric Dataflow: Programming Model, Scheduling, and Application to Heterogeneous MPSoC

International audienceEfficient programming of signal processing applications on embedded systems is a complex problem. High level models such as Synchronous dataflow (SDF) have been privileged candidates for dealing with this complexity. These models permit to express inherent application parallelism, as well as analysis for both verification and optimization. Parametric dataflow models aim at providing sufficient dynamicity to model new applications, while at the same time maintaining the high level of analyzability needed for efficient real life implementations. This paper presents a new compilation flow that targets parametric dataflows. Built on the LLVM compiler infrastructure, it offers an actor based C++ programming model to describe parametric graphs, a compilation front-end providing graph analysis features, and a retargetable back-end to map the application on real hardware. This paper gives an overview of this flow, with a specific focus on scheduling. The crucial gap between dataflow models and real hardware on which actor firing is not atomic, as well as the consequences on FIFOs sizing and execution pipelining are taken into account.The experimental results illustrate our compilation flow applied to compilation of 3GPP LTE-Advanced demodulation on a heterogeneous MPSoC with distributed scheduling features. This achieves performances similar to time-consuming hand made optimizations

To respond or not to respond - a personal perspective of intestinal tolerance

For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research

CD25-Treg-depleting antibodies preserving IL-2 signaling on effector T cells enhance effector activation and antitumor immunity.

Intratumoral regulatory T cell (Treg) abundance associates with diminished anti-tumor immunity and poor prognosis in human cancers. Recent work demonstrates that CD25, the high affinity receptor subunit for IL-2, is a selective target for Treg depletion in mouse and human malignancies; however, anti-human CD25 antibodies have failed to deliver clinical responses against solid tumors due to bystander IL-2 receptor signaling blockade on effector T cells, which limits their anti-tumor activity. Here we demonstrate potent single-agent activity of anti-CD25 antibodies optimized to deplete Tregs whilst preserving IL-2-STAT5 signaling on effector T cells, and demonstrate synergy with immune checkpoint blockade in vivo. Pre-clinical evaluation of an anti-human CD25 (RG6292) antibody with equivalent features demonstrates, in both non-human primates and humanized mouse models, efficient Treg depletion with no overt immune-related toxicities. Our data supports the clinical development of RG6292 and evaluation of novel combination therapies incorporating non-IL-2 blocking anti-CD25 antibodies in clinical studies

Systemic IL-12 Administration Alters Hepatic Dendritic Cell Stimulation Capabilities

The liver is an immunologically unique organ containing tolerogenic dendritic cells (DC) that maintain an immunosuppressive microenvironment. Although systemic IL-12 administration can improve responses to tumors, the effects of IL-12-based treatments on DC, in particular hepatic DC, remain incompletely understood. In this study, we demonstrate systemic IL-12 administration induces a 2–3 fold increase in conventional, but not plasmacytoid, DC subsets in the liver. Following IL-12 administration, hepatic DC became more phenotypically and functionally mature, resembling the function of splenic DC, but differed as compared to their splenic counterparts in the production of IL-12 following co-stimulation with toll-like receptor (TLR) agonists. Hepatic DCs from IL-12 treated mice acquired enhanced T cell proliferative capabilities similar to levels observed using splenic DCs. Furthermore, IL-12 administration preferentially increased hepatic T cell activation and IFNγ expression in the RENCA mouse model of renal cell carcinoma. Collectively, the data shows systemic IL-12 administration enables hepatic DCs to overcome at least some aspects of the inherently suppressive milieu of the hepatic environment that could have important implications for the design of IL-12-based immunotherapeutic strategies targeting hepatic malignancies and infections

τC: C with process network extensions for embedded manycores

Conference of 14th Annual International Conference on Computational Science, ICCS 2014 ; Conference Date: 10 June 2014 Through 12 June 2014; Conference Code:105783International audienceCurrent and future embedded manycore systems bring complex and heterogeneous architectures with a large number of processing cores, making both parallel programming at this scale and understanding the architecture itself a daunting task. Process Networks and other dataflow based Models of Computation (MoC) are a good base to present a universal model of the underlying manycore architectures to the programmer. If a language exposes a simple to grasp MoC in a consistent way across architectures, the programmer can concentrate the efforts on optimizing the expression of parallelism in the application instead of porting code to a given system. In this paper, we present a process network extension to C called τC and its mapping to both a POSIX target and the P2012/STHORM platform, and show how the language offers an architecture independent solution of this problem

A model of computation for real-time applications on embedded manycores

Conference of 2014 8th IEEE International Symposium on Embedded Multicore/Manycore SoCs, MCSoC 2014 ; Conference Date: 23 September 2014 Through 25 September 2014; Conference Code:109143International audienceThis paper presents a first work to bring a consistent Model of Computation (MoC) for real-time applications on embedded many-core systems. Embedded manycores have lots of constraints (power, heterogeneity, memory, etc.) but also lots of promises with regard to harness able applications, i.e. New kinds of applications that could fit embedded systems. Such a MoC would encompass both data movements in Manycore's memories, determinism of execution, composability but also real-time requirements. We build our MoC on a well known base - CycloStatic Data Flow (CSDF) - for its desirable properties (i.e. Determinism and composability), and thank to several case-studies, we extend it to a superset, adding two special data processing filters which preserve these good properties and provide useful features for embedded computing

Automatic Streamization of Image Processing Applications

International audienceNew many-core architectures such as the Kalray MPPA-256 provide energy-efficiency and high performance for embedded systems. However, to take advantage of these opportunities, careful manual op-timizations are required. We investigate the automatic streamization of image processing applications, implemented in C on top of a dedicated API, onto this target accessed through the ΣC dataflow language. We discuss compiler and runtime design choices and their impact on perfor-mance. Our compilation techniques are implemented as source-to-source transformations in the PIPS open-source compilation framework. Ex-periments show lowest energy consumption on the Kalray MPPA target compared to other hardware targets for a range of 8 test applications