Evolution of the BFQ Storage-I/O scheduler

An accurate storage-I/O scheduler, named Budget Fair Queueing (BFQ), was integrated with a special set of heuristics a few years ago. The resulting, improved scheduler, codenamed BFQ-v1, was able to guarantee a number of desirable service properties, including a high responsiveness, to applications and system services. In the intervening years, BFQ-v1 has become relatively popular on desktop and handheld systems, and has further evolved. But no official, comprehensive and concentrated documentation has been provided about the improvements that have followed each other. In this paper we fill this documentation gap, by describing the current, last version of BFQ (v7r8). We also show the performance of BFQ-v7r8 through some experimental results, in terms of throughput and application responsiveness, and on both an HDD and an SSD

Integrating Linux and the real-time ERIKA OS through the Xen hypervisor

Modern user interfaces grow more and more complex and cannot be possibly handled by the same software components in charge of the timely execution of safety-critical control tasks. Evidence Srl recently proposed a single-board dual-OS system aimed at combining the flexibility of the Linux general-purpose operating system, which is able to produce any complex user interface, and the reliability of the automotive-grade ERIKA Enterprise operating system, a small-footprint real-time OS suitable for safety-critical control tasks and able to execute commands triggered by Linux. The operating systems run on dedicated cores and, for efficiency reasons, they share memory with limited support for memory protection: although the system allows running two operating systems, from a safety certification point of view it suffers from the fact that safety-critical and non-safety-critical components should be isolated from each other. In this paper we present, as an improvement to the initial implementation, again a double-OS system running, on a dual-core platform, ERIKA Enterprise and a full-featured Linux OS, but using the Xen hypervisor to run the two operating systems in two isolated domains. In the proposed setup, each of the domains runs on a dedicated core, assigned statically by the hypervisor. Linux runs as the control domain, and is therefore able to execute any of the components of the Xen toolstack; it is also able to grant to the real-time operating system access to any I/O-memory range needed for control tasks. The described system also provides a simple, safe communication mechanism between the two operating systems, based on Xen's inter-domain event notification primitives and explicit sharing of a dedicated set of memory pages by the real-time operating system

Neuroaesthetics of Art Vision: an Experimental Approach to the Sense of Beauty

Objective NEVArt research aims to study the correlation between a set of neurophysiological/emotional reactions and the level of aesthetic appreciation of around 500 experimental subjects during the observation of 18 different paintings from the XVI-XVIII century in a real museum context. Methods Several bio-signals have been recorded to evaluate the participants’ reactions during the observation of paintings. Among them: (a) neurovegetative, motor and emotional biosignals were recorded using wearable tools for EEG (electroencephalogram), ECG (electrocardiogram) and EDA (electrodermal activity); (b) gaze pattern during the observation of art works, while (c) data of the participants (age, gender, education, familiarity with art, etc.) and their explicit judgments about paintings have been obtained. Participants were invited to respond during the observation of paintings, reporting the degree of pleasantness, perceived movement and familiarity with the painted subject. Results Each recorded bio-signal will be correlated with the explicit evaluations obtained by participants during the museum experience. These results may contribute to enlarge the theoretical framework on the physiological, cognitive and emotional responses of people when viewing pictorial artworks. Conclusion The NEVArt research, both in term of technical skills and upgrade in neuroscientific awareness, can be the basis to proceed with a set of further research topics in the near future. Ground-breaking and statistically significant observations can be derived from the present research, mainly at the biological, medical and didactical point of view by paving the way for many other multidisciplinary research developments on art exhibit, architecture, etc