Thermal Management in Fault-Tolerant Mixed-Criticality Multicore Systems

, M.Sc. Thesis Sharif University of Technology Gohari Nazari, Pourya (Author) ; Hessabi, Shahin (Supervisor)

Abstract

The increasing complexity of embedded systems has led to the integration of tasks with various degrees of criticality on a common hardware platform called a mixed-criticality system. These systems typically exploit the inherent redundancy of multicore systems to employ the fault-tolerant techniques to satisfy the required target reliability. On the other hand, the use of fault-tolerant techniques increases the time that cores are simultaneously active with maximum power, which can violate the thermal design power (TDP) and exceed the safe temperature of the chip. This activates the dynamic thermal manage- ment (DTM) technique. Some of the most well-known methods to reduce the chip surface...

TherMa-MiCs: Thermal-Aware scheduling for fault-tolerant mixed-criticality systems

, Article IEEE Transactions on Parallel and Distributed Systems ; Volume 33, Issue 7 , 2022 , Pages 1678-1694 ; 10459219 (ISSN) Safari, S ; Khdr, H ; Gohari Nazari, P ; Ansari, M ; Hessabi, S ; Henkel, J ; Sharif University of Technology

IEEE Computer Society 2022

Abstract

Multicore platforms are becoming the dominant trend in designing Mixed-Criticality Systems (MCSs), which integrate applications of different levels of criticality into the same platform. A well-known MCS is the dual-criticality system that is composed of low-criticality and high-criticality tasks. The availability of multiple cores on a single chip provides opportunities to employ fault-Tolerant techniques, such as N-Modular Redundancy (NMR), to ensure the reliability of MCSs. However, applying fault-Tolerant techniques will increase the power consumption on the chip, and thereby on-chip temperatures might increase beyond safe limits. To prevent thermal emergencies, urgent countermeasures,...

Power-Aware checkpointing for multicore embedded systems

, Article IEEE Transactions on Parallel and Distributed Systems ; Volume 33, Issue 12 , 2022 , Pages 4410-4424 ; 10459219 (ISSN) Ansari, M ; Safari, S ; Khdr, H ; Gohari Nazari, P ; Henkel, J ; Ejlali, A ; Hessabi, S ; Sharif University of Technology

IEEE Computer Society 2022

Abstract

Increasing the number of cores integrated on a single chip offers a great potential for the implementation of fault-tolerant techniques to achieve high reliability in real-time embedded systems. Checkpointing with rollback-recovery is a well-established technique to tolerate transient faults in multicore platforms. To consider the worst-case fault occurrence scenario, checkpointing technique requires to re-execute some parts of the tasks, and that might lead to simultaneous execution of task parts with high power consumptions, which eventually might result in a peak power increase beyond the thermal design power (TDP). Exceeding TDP can elevate on-chip temperatures beyond safe limits, and...

Graphic: Graph-based hierarchical clustering for single-molecule localization microscopy

, Article 18th IEEE International Symposium on Biomedical Imaging, ISBI 2021, 13 April 2021 through 16 April 2021 ; Volume 2021-April , 2021 , Pages 1892-1896 ; 19457928 (ISSN); 9781665412469 (ISBN) Pourya, M ; Aziznejad, S ; Unser, M ; Sage, D ; Sharif University of Technology

IEEE Computer Society 2021

Abstract

We propose a novel method for the clustering of point-cloud data that originate from single-molecule localization microscopy (SMLM). Our scheme has the ability to infer a hierarchical structure from the data. It takes a particular relevance when quantitatively analyzing the biological particles of interest at different scales. It assumes a prior neither on the shape of particles nor on the background noise. Our multiscale clustering pipeline is built upon graph theory. At each scale, we first construct a weighted graph that represents the SMLM data. Next, we find clusters using spectral clustering. We then use the output of this clustering algorithm to build the graph in the next scale; in...

READY: Reliability-and deadline-aware power-budgeting for heterogeneous multi-core systems

, Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; 2020 Saber Latibari, J ; Ansari, M ; Gohari Nazari, P ; Yari Karin, S ; Hosseini Monazzah, A. M ; Ejlali, A ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2020

Abstract

Tackling the dark silicon problem in a heterogeneous multi-core system, the temperature constraints across the system should be addressed carefully by assigning a proper set of tasks to a pool of the heterogeneous cores during the run-time. When such a system is utilized in a reliable/realtime application, the reliability/timing constraints of the application should also be augmented to the temperature constraints and make the tasks mapping problem more and more complex. To solve the mapping problem in such a situation, we propose READY; an online reliability-and deadline-aware mapping and scheduling algorithm for heterogeneous multi-core systems. READY utilizes an adaptive power constraint...

READY: Reliability-and deadline-aware power-budgeting for heterogeneous multicore systems

, Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; Volume 40, Issue 4 , 2021 , Pages 646-654 ; 02780070 (ISSN) Saber Latibari, J ; Ansari, M ; Gohari Nazari, P ; Yari Karin, S ; Hosseini Monazzah, A. M ; Ejlali, A ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2021

Abstract

Tackling the dark silicon problem in a heterogeneous multicore system, the temperature constraints across the system should be addressed carefully by assigning a proper set of tasks to a pool of the heterogeneous cores during the run-time. When such a system is utilized in a reliable/real-time application, the reliability/timing constraints of the application should also be augmented to the temperature constraints and make the tasks mapping problem more and more complex. To solve the mapping problem in such a situation, we propose READY; an online reliability-and deadline-aware mapping and scheduling algorithm for heterogeneous multicore systems. READY utilizes an adaptive power constraint...

Thermal-aware standby-sparing technique on heterogeneous real-time embedded systems

, Article IEEE Transactions on Emerging Topics in Computing ; 2021 ; 21686750 (ISSN) Ansari, M ; Safari, S ; Yari Karin, S ; Gohari Nazari, P ; Khdr, H ; Shafique, M ; Henkel, J ; Ejlali, A ; Sharif University of Technology

IEEE Computer Society 2021

Abstract

Low power consumption, real-time computing, and high reliability are three key requirements/design objectives of real-time embedded systems. The standby-sparing technique can improve system reliability while it might increase the temperature of the system beyond safe limits. In this paper, we propose a thermal-aware standby-sparing (TASS) technique that aims at maximizing the Quality of Service (QoS) of soft real-time tasks, which is defined as a function of the finishing time of running tasks. The proposed technique tolerates permanent and transient faults for multicore real-time embedded systems while meeting the Thermal Safe Power (TSP) as the core-level power constraint, which avoids...

Thermal-Aware standby-sparing technique on heterogeneous real-time embedded systems

, Article IEEE Transactions on Emerging Topics in Computing ; Volume 10, Issue 4 , 2022 , Pages 1883-1897 ; 21686750 (ISSN) Ansari, M ; Safari, S ; Yari Karin, S ; Gohari Nazari, P ; Khdr, H ; Shafique, M ; Henkel, J ; Ejlali, A ; Sharif University of Technology

IEEE Computer Society 2022

Abstract

Low power consumption, real-time computing, and high reliability are three key requirements/design objectives of real-time embedded systems. The standby-sparing technique can improve system reliability while it might increase the temperature of the system beyond safe limits. In this paper, we propose a thermal-aware standby-sparing (TASS) technique that aims at maximizing the Quality of Service (QoS) of soft real-time tasks, which is defined as a function of the finishing time of running tasks. The proposed technique tolerates permanent and transient faults for multicore real-time embedded systems while meeting the Thermal Safe Power (TSP) as the core-level power constraint, which avoids...

Numerical Modeling of Liquid Jet Breakup Using SPH Method

, M.Sc. Thesis Sharif University of Technology Pourabdian, Majid (Author) ; Morad , Mohammad Reza (Supervisor) ; Omidvar, Pourya (Supervisor)

Abstract

Smoothed Particle Hydrodynamics (SPH) is a numerical Lagrangian meshless method which has numerous applications in astrophysics, hydrodynamics, free-surface flows, jets and sprays formation. Atomization of continuum liquid to fine droplets or in other words, liquid breakup processes are emerged in many engineering applications such as fuel sprays inside the combustion chamber of internal combustion engines that sizes of produced sprays significantly influence the engine’s efficiency. This research is accomplished to investigate the one-phase and two-phase flows of liquid jet breakup. For this aim, an open source code called SPHysics which solves the flow field by SPH method is utilized. This...

ATLAS: aging-aware task replication for multicore safety-critical systems

, Article Proceedings of the IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS ; Volume 2023-May , 2023 , Pages 223-234 ; 15453421 (ISSN); 979-835032176-0 (ISBN) Ansari, M ; Safari, S ; Yeganeh Khaksar, A ; Siyadatzadeh, R ; Gohari Nazari, P ; Khdr, H ; Shafiquen, M ; Henkel, J ; Ejlali, A ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2023

Abstract

A major requirement of safety-critical systems is high reliability at low power consumption. Dynamic voltage and frequency (v/f) scaling (DVFS) techniques are widely exploited to reduce power consumption. However, DVFS through downscaling v/f levels has a negative impact on the reliability of the tasks running on the cores, and through upscaling v/f levels has circuitlevel aging effects. To achieve high reliability in multicore safetycritical systems, task replication as a fault-tolerant technique is an established way to deal with the negative effect of downscaling v/f levels, but it may accelerate aging effects due to elevating the on-chip temperatures. In this paper, we propose an...

Drop formation from a capillary tube: comparison of different bulk fluid on newtonian drops and formation of newtonian and non-newtonian drops in air using image processing

, Article International Journal of Heat and Mass Transfer ; Volume 124 , 2018 , Pages 912-919 ; 00179310 (ISSN) Nazari, A ; Zadkazemi Derakhshi, A ; Nazari, A ; Firoozabadi, B ; Sharif University of Technology

2018

Abstract

The formation of water drops as a Newtonian fluid and formation of a shear-thinning non-Newtonian fluid, Carboxyl Methyl Cellulose (CMC) from a capillary into different bulk fluids are experimentally investigated. A high speed camera is used to visualize the images of the drops and an image-processing code employed to determine the drop properties from each image. It was found that the properties of the water drops when they are drooped into the liquids bulk fluids such as toluene and n-hexane are almost the same while they differed substantially when they were drooped into the air bulk fluid. It is shown that during the formation of water drop in all three kinds of bulk fluids, the drop...

Infeasibility proof and information state in network information theory

, Article IEEE Transactions on Information Theory ; Vol. 60, Issue. 10 , 2014 , Pages 5992-6004 ; ISSN: 00189448 Gohari, A ; Anantharam, V ; Sharif University of Technology

2014

Abstract

In this paper, we revisit the structure of infeasibility results in network information theory, based on a notion of information state. We also discuss ideas for generalizing a known outer bound for lossless transmission of independent sources over a network to one of lossy transmission of dependent sources over the same network. To concretely demonstrate this, we apply our ideas and prove new results for lossy transmission of dependent sources by generalizing: 1) the cut-set bound; 2) the best known outer bound on the capacity region of a general broadcast channel; and 3) the outer bound part of the result of Maric, Yates, and Kramer on strong interference channels with a common message

Comments on 'Information-Theoretic Key Agreement of Multiple Terminals - Part I'

, Article IEEE Transactions on Information Theory ; Volume 63, Issue 8 , 2017 , Pages 5440-5442 ; 00189448 (ISSN) Gohari, A ; Anantharam, V ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2017

Abstract

Theorem 5 of A. Gohari, V. Anantharam, IEEE Transactions on Information Theory, vol. 56, no. 8, pp. 3973-3996, 2010, states an upper bound on the secrecy capacity for the source model problem. It has a three page proof given in Appendix B of the paper. Unfortunately, we show that this bound does not provide any improvement over the simpler bound given in Corollary 1 of the paper. We also provide an example of a family of two agent source model problems where the one-way secrecy rate in each direction is zero, but the secrecy rate is nonzero and can be determined exactly as a conditional mutual information. © 1963-2012 IEEE

Generating dependent random variables over networks

, Article 2011 IEEE Information Theory Workshop, ITW 2011 ; 2011 , Pages 698-702 ; 9781457704376 (ISBN) Gohari, A. A ; Anantharam, V ; Sharif University of Technology

2011

Abstract

In this paper we study the problem of generation of dependent random variables, known as the coordination capacity [4], [5], in multiterminal networks. In this model m nodes of the network are observing i.i.d. repetitions of X (1), X (2),⋯, X (m) distributed according to q(x (1),⋯, x (m)). Given a joint distribution q(x (1),⋯,x (m), y (1), ⋯, y (m)), the final goal of the i th node is to construct the i.i.d. copies of Y (i) after the communication over the network where X (1), X (2),⋯, X (m), Y (1), Y (2),⋯, Y (m) are jointly distributed according to q(x (1), , x (m), y (1),⋯,y (m)). To do this, the nodes can exchange messages over the network at rates not exceeding the capacity constraints...

Critical graphs in index coding

, Article IEEE International Symposium on Information Theory - Proceedings ; 2014 , p. 281-285 Tahmasbi, M ; Shahrasbi, A ; Gohari, A ; Sharif University of Technology

2014

Abstract

In this paper we define critical graphs as minimal graphs that support a given set of rates for the index coding problem, and study them for both the one-shot and asymptotic setups. For the case of equal rates, we find the critical graph with minimum number of edges for both one-shot and asymptotic cases. For the general case of possibly distinct rates, we show that for one-shot and asymptotic linear index coding, as well as asymptotic non-linear index coding, each critical graph is a union of disjoint strongly connected subgraphs (USCS). On the other hand, we identify a non-USCS critical graph for a one-shot non-linear index coding problem. In addition, we show that the capacity region of...

When is it possible to simulate a DMC channel from another?

, Article 2013 IEEE Information Theory Workshop, ITW 2013 ; Sept , 2013 , Page(s): 1 - 5 ; 9781479913237 (ISBN) Haddadpour, F ; Yassaee, M. H ; Aref, M. R ; Gohari, A

2013

Abstract

In this paper, we study the problem of simulating a DMC channel from another DMC channel. We assume that the input to the channel we are simulating is i.i.d. and that the transmitter and receivers are provided with common randomness at limited rates. We prove bounds for simulating point-to-point, MAC and broadcast channels. As a special case, we recover the achievability part of the result of Cuff for point-to-point channel simulation via a noiseless link and shared randomness

On Marton's inner bound for broadcast channels

, Article IEEE International Symposium on Information Theory - Proceedings, 1 July 2012 through 6 July 2012 ; July , 2012 , Pages 581-585 ; 9781467325790 (ISBN) Gohari, A ; Nair, C ; Anantharam, V ; Sharif University of Technology

2012

Abstract

Marton's inner bound is the best known achievable region for a general discrete memoryless broadcast channel. To compute Marton's inner bound one has to solve an optimization problem over a set of joint distributions on the input and auxiliary random variables. The optimizers turn out to be structured in many cases. Finding properties of optimizers not only results in efficient evaluation of the region, but it may also help one to prove factorization of Marton's inner bound (and thus its optimality). The first part of this paper formulates this factorization approach explicitly and states some conjectures and results along this line. The second part of this paper focuses primarily on the...

Deterministic randomness extraction from generalized and distributed santha-vazirani sources

, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 6 July 2015 through 10 July 2015 ; Volume 9134 , 2015 , Pages 143-154 ; 03029743 (ISSN) ; 9783662476710 (ISBN) Beigi, S ; Etesami, O ; Gohari, A ; Sharif University of Technology

Springer Verlag 2015

Abstract

A Santha-Vazirani (SV) source is a sequence of random bits where the conditional distribution of each bit, given the previous bits, can be partially controlled by an adversary. Santha and Vazirani show that deterministic randomness extraction from these sources is impossible. In this paper, we study the generalization of SV sources for nonbinary sequences. We show that unlike the binary case, deterministic randomness extraction in the generalized case is sometimes possible. We present a necessary condition and a sufficient condition for the possibility of deterministic randomness extraction. These two conditions coincide in “non-degenerate” cases. Next, we turn to a distributed setting. In...

The value of information-theoretic content of help bits for computation

, Article IWCIT 2015 - Iran Workshop on Communication and Information Theory, 6 May 2015 through 7 May 2015 ; 2015 ; 9781479982356 (ISBN) Beigi, S ; Etesami, O ; Gohari, A ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2015

Abstract

'Help bits' are some limited trusted information about an instance or instances of a computational problem that may reduce the computational complexity of solving that instance or instances. Assume that we can efficiently solve k instances of a decision problem using some help bits whose entropy is less than k when the k instances are drawn independently from a particular distribution. Then there is an upper bound on the average-case complexity of the problem, namely we can efficiently solve an instance drawn from that distribution correctly with probability better than 1/2

The value of help bits in randomized and average-case complexity

, Article Computational Complexity ; Volume 26, Issue 1 , 2017 , Pages 119-145 ; 10163328 (ISSN) Beigi, S ; Etesami, O ; Gohari, A ; Sharif University of Technology

Birkhauser Verlag AG 2017

Abstract

“Help bits" are some limited trusted information about an instance or instances of a computational problem that may reduce the computational complexity of solving that instance or instances. In this paper, we study the value of help bits in the settings of randomized and average-case complexity. If k instances of a decision problem can be efficiently solved using ℓ< k help bits, then without access to help bits one can efficiently compute a k-bit vector that is not equal to the k-bit vector of solutions to the k instances. A decision problem with this property is called k-membership comparable. Amir, Beigel, and Gasarch (1990) show that for constant k, all k-membership comparable languages...