Task and Memory Mapping Optimization for SDRAM Interference Minimization on Heterogeneous MPSoCs

DDR SDRAM memories are resources commonly used on multicore platforms and hence, being a main source of interference. To deal with this issue, we propose a methodology based on task/memory mapping optimization through multi-objective heuristic-based algorithms. By placing the tasks on the platform cores and the memory in the DDR SDRAM banks, we minimize the DDR SDRAM interference while considering other aspects such as the task execution parallelism and deadline margin. To evaluate the fitness of the task/memory map, the optimization algorithms make use of cost function equations. In order to compute the DDR memory interference cost, we use a fast executing self-designed cost function. The execution parallelism is computed using the workload variance cost function. The deadline margin of a task is computed considering the inter and intra core interference. The task/memory mapping outcomes are checked through tests for which the heterogeneous MPSoCs Keystone II and Sitara AM5728 are used. To assure certification, the WCET constraints of the resulting near-optimal Pareto solutions are verified through formally validated bounding frameworks

Heterogeneous multicore SDRAM interference analysis

The purpose of this paper is to describe a set of DDR3 SDRAM interference estimation cost functions. The arbitration system of the SDRAM controller heavily impact the interference analysis. In this work, three arbitration are considered, corresponding to the situations where the accessed memory address belongs to the same block address, different memory banks and different rows. The aim of these functions is to estimate the instructions interference overhead may suffer when concurrently accessing these three logical addresses in a SDRAM saturation context. To develop these interference expressions, specific measurement systems, micro-benchmarks and theory on SDRAM controllers have been used

Towards an efficient cost function equation for DDR SDRAM interference analysis on heterogeneous MPSoCs

Real-time applications must finish their execution within an imposed deadline to function correctly. DDR memory interference on multicore platforms can make tasks overpass their respective deadline, leading to critical errors. Bandwidth regulators and SDRAM bank partitioning are examples of techniques used to mitigate or avoid this interference type. Another possibility is to optimally place tasks and memory on the platform, i.e., task/memory mapping optimization. The algorithms used for finding optimal mapping solutions work using a cost function that indicates the fitness of the found solution. In this work, we propose a DDR SDRAM cost function that estimates the worst-case execution time for a giving map, and hence, implementable in an optimization algorithm. Our cost function considers the DDR memory device operation, the SoC manufacturer memory controller, the heterogeneity of the platform and the characteristics of the tasks to map. The cost function is evaluated by measuring directly the interference from the heterogeneous MPSoCs Keystone II and Sitara AM5728 by Texas Instruments

Core-Shell Palladium/MOF Platforms as Diffusion-Controlled Nanoreactors in Living Cells and Tissue Models

Translating the potential of transition metal catalysis to biological and living environments promises to have a profound impact in chemical biology and biomedicine. A major challenge in the field is the creation of metal-based catalysts that remain active over time. Here, we demonstrate that embedding a reactive metallic core within a microporous metal-organic framework-based cloak preserves the catalytic site from passivation and deactivation, while allowing a suitable diffusion of the reactants. Specifically, we report the fabrication of nanoreactors composed of a palladium nanocube core and a nanometric imidazolate framework, which behave as robust, long-lasting nanoreactors capable of removing propargylic groups from phenol-derived pro-fluorophores in biological milieu and inside living cells. These heterogeneous catalysts can be reused within the same cells, promoting the chemical transformation of recurrent batches of reactants. We also report the assembly of tissue-like 3D spheroids containing the nanoreactors and demonstrate that they can perform the reactions in a repeated mannerThe authors thank the financial support of the MINECO ( CTQ2017-89588-R , SAF2016-76689-R , CTQ2017-84767-P , RYC-2014-16962 , and RYC-2017-23457 ), the Xunta de Galicia ( ED431F 2017/02 , 2015-CP082 , ED431C 2017/19 , and Centro singular de investigación de Galicia accreditation 2019-2022, ED431G 2019/03 ), the European Union (European Regional Development Fund [ERDF]; H2020-MSCA-IF-2016 grant agreement no. 749667 ; and INTERREG V-A Spain-Portugal [POCTEP] 2014-2020, project 0624_2IQBIONEURO_6_E ), and the European Research Council (advanced grant no. 340055 ). Support of the orfeo-cinqa network ( CTQ2016-81797-REDC ) is also kindly acknowledgedS

Multicore shared memory interference analysis through hardware performance counters

International audienceThe aim of this paper is to present a high precision and event-versatile MBPTA framework that we have developed for the statistical timing analysis of multicore platforms. Its use satisfactorily allows the study of complex multicore platforms from the CPU point of view, without requiring hardware or software models. This gives us an accurate real view of the platform behavior for any specific situation without using extra tools. In addition, this measurement framework is directly portable to other multicore platforms with the same CPU version and easily portable to other CPU versions within the same manufacturer.The MBPTA framework directly uses coprocessors and the Performance Monitor Unit (PMU), i.e. Performance Monitor Hardware (PMH), instead of software profilers. Hardware performance counters provide low-overhead access to a considerable amount of performance information of numerous elements such as the CPU, caches or bus.The statistical timing analysis consists in proposing average and worst-case modeling by making use of the tool diagXtrm applied to measurement of task execution times.Measurements obtained from the PMH are used for analyzing and quantifying the interference that can happen within a multicore platform.The potential for measurements from coprocessor and PMU, as well as its potential for statistical analysis, is shown by using an heterogeneous multicore Texas Instrument system on chip. The interference we focus on are due to the shared memory of this platform

Targeting cancer stem cell OXPHOS with tailored ruthenium complexes as a new anti-cancer strategy

Abstract Background Previous studies by our group have shown that oxidative phosphorylation (OXPHOS) is the main pathway by which pancreatic cancer stem cells (CSCs) meet their energetic requirements; therefore, OXPHOS represents an Achille’s heel of these highly tumorigenic cells. Unfortunately, therapies that target OXPHOS in CSCs are lacking. Methods The safety and anti-CSC activity of a ruthenium complex featuring bipyridine and terpyridine ligands and one coordination labile position (Ru1) were evaluated across primary pancreatic cancer cultures and in vivo, using 8 patient-derived xenografts (PDXs). RNAseq analysis followed by mitochondria-specific molecular assays were used to determine the mechanism of action. Results We show that Ru1 is capable of inhibiting CSC OXPHOS function in vitro, and more importantly, it presents excellent anti-cancer activity, with low toxicity, across a large panel of human pancreatic PDXs, as well as in colorectal cancer and osteosarcoma PDXs. Mechanistic studies suggest that this activity stems from Ru1 binding to the D-loop region of the mitochondrial DNA of CSCs, inhibiting OXPHOS complex-associated transcription, leading to reduced mitochondrial oxygen consumption, membrane potential, and ATP production, all of which are necessary for CSCs, which heavily depend on mitochondrial respiration. Conclusions Overall, the coordination complex Ru1 represents not only an exciting new anti-cancer agent, but also a molecular tool to dissect the role of OXPHOS in CSCs. Results indicating that the compound is safe, non-toxic and highly effective in vivo are extremely exciting, and have allowed us to uncover unprecedented mechanistic possibilities to fight different cancer types based on targeting CSC OXPHOS