Identifying Unexpected Inter-core Interference Induced by Shared Cache

Denis Hoornaert; Shahin Roozkhosh; Renato Mancuso; Marco Caccamo

Publications Memory & Shared-Resource Management

Identifying Unexpected Inter-core Interference Induced by Shared Cache

Denis Hoornaert, Shahin Roozkhosh, Renato Mancuso, Marco Caccamo

WiP Session @ 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021), May 2021, Online

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Fig. 1: Schematic view of the considered setup with the partitioning of the core cluster (both cores and LLC) on the left, the different path taken by the transactions highlighted in cyan, orange and red, and the AXI-Regulator on the right.

Abstract

In modern real-time multicore systems, understanding and adequately managing shared caches is essential to ensure the temporal isolation of critical tasks. Recent research has identified and extensively studied the sources of unpredictability imputable to shared caches, heavily promoting techniques such as cache partitioning and internal resources management. In this article, we highlight the existence of an enigmatic source of inter-core interference: the CPU-brainfreeze. Experiments realized on a development board show that benchmarks (selected from the San-Diego Vision Benchmark Suite) can exhibit up to a 10-fold increase in their execution time. The same experiment shows that for extreme cases, the core cluster can be stalled indefinitely.

Code and hardware artifacts

Jailhouse-RT Software Used or cited in this paper
A fork of the Jailhouse partitioning hypervisor with experimental real-time features.

Cite this paper

@inproceedings{brainfreeze_RTAS_wip_21,
  title     = {{Identifying Unexpected Inter-core Interference Induced by Shared Cache}},
  author    = {Hoornaert, Denis and Roozkhosh, Shahin and Mancuso, Renato and Caccamo, Marco},
  booktitle = {WiP Session @ 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021)},
  year      = 2021,
  month     = may,
  address   = {Online},
  url       = {https://cs-people.bu.edu/rmancuso/files/papers/CPU_Brainfreeze_RTAS21_WiP.pdf}
}

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TY  - CONF
AU  - Hoornaert, Denis
AU  - Roozkhosh, Shahin
AU  - Mancuso, Renato
AU  - Caccamo, Marco
TI  - Identifying Unexpected Inter-core Interference Induced by Shared Cache
T2  - WiP Session @ 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021)
PY  - 2021
DA  - 2021/05//
CY  - Online
AB  - In modern real-time multicore systems, understanding and adequately managing shared caches is essential to ensure the temporal isolation of critical tasks. Recent research has identified and extensively studied the sources of unpredictability imputable to shared caches, heavily promoting techniques such as cache partitioning and internal resources management. In this article, we highlight the existence of an enigmatic source of inter-core interference: the CPU-brainfreeze. Experiments realized on a development board show that benchmarks (selected from the San-Diego Vision Benchmark Suite) can exhibit up to a 10-fold increase in their execution time. The same experiment shows that for extreme cases, the core cluster can be stalled indefinitely.
ER  -

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%0 Conference Paper
%A Hoornaert, Denis
%A Roozkhosh, Shahin
%A Mancuso, Renato
%A Caccamo, Marco
%T Identifying Unexpected Inter-core Interference Induced by Shared Cache
%B WiP Session @ 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021)
%D 2021
%C Online
%X In modern real-time multicore systems, understanding and adequately managing shared caches is essential to ensure the temporal isolation of critical tasks. Recent research has identified and extensively studied the sources of unpredictability imputable to shared caches, heavily promoting techniques such as cache partitioning and internal resources management. In this article, we highlight the existence of an enigmatic source of inter-core interference: the CPU-brainfreeze. Experiments realized on a development board show that benchmarks (selected from the San-Diego Vision Benchmark Suite) can exhibit up to a 10-fold increase in their execution time. The same experiment shows that for extreme cases, the core cluster can be stalled indefinitely.

Download .enw

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    {
        "id": "brainfreeze_RTAS_wip_21",
        "type": "paper-conference",
        "title": "Identifying Unexpected Inter-core Interference Induced by Shared Cache",
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                "given": "Denis"
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        "publisher-place": "Online",
        "abstract": "In modern real-time multicore systems, understanding and adequately managing shared caches is essential to ensure the temporal isolation of critical tasks. Recent research has identified and extensively studied the sources of unpredictability imputable to shared caches, heavily promoting techniques such as cache partitioning and internal resources management. In this article, we highlight the existence of an enigmatic source of inter-core interference: the CPU-brainfreeze. Experiments realized on a development board show that benchmarks (selected from the San-Diego Vision Benchmark Suite) can exhibit up to a 10-fold increase in their execution time. The same experiment shows that for extreme cases, the core cluster can be stalled indefinitely."
    }
]

Download .json

D. Hoornaert, S. Roozkhosh, R. Mancuso, and M. Caccamo, “Identifying Unexpected Inter-core Interference Induced by Shared Cache,” in WiP Session @ 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021), May. 2021.

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Hoornaert, D., Roozkhosh, S., Mancuso, R., & Caccamo, M. (2021). Identifying Unexpected Inter-core Interference Induced by Shared Cache. In WiP Session @ 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021).

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