Processor reliability enhancement through compiler-directed register file peak temperature reduction

Abstract—Each semiconductor technology generation brings us closer to the imminent processor architecture heat wall, with all its associated adverse effects on system performance and reliability. Temperature hotspots not only accelerate the physical failure mechanisms such as electromigration and di-electric breakdown, but furthermore make the system more vulnerable to timing-related intermittent failures. Traditional thermal management techniques suffer from considerable per-formance overhead as the entire processor needs to be stalled or slowed down to preclude heat accumulation. Given the significant temporal and spatial variations of the chip-wide temperature, we propose in this paper a technique that directly targets one of the resources that is most likely to overheat in current processors, namely, the register files. Instead of duplicating or physically distributing the register file, we suggest to attain power density control through exploiting the extant spatial slack associated with register file accesses. Based on application-specific access profiles, a compiler-directed register shuffling strategy is proposed to deterministically construct the logical to physical register map-ping in a rotating manner. Simulation results confirm that the proposed technique attains, within a limited hardware budget and negligible performance degradation, effective reduction in peak temperature and hence in the expected fault rates for the entire chip. I

Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst

The recently discovered neutron star transient Swift J0243.6+6124 has been monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT). Based on the obtained data, we investigate the broadband spectrum of the source throughout the outburst. We estimate the broadband flux of the source and search for possible cyclotron line in the broadband spectrum. No evidence of line-like features is, however, found up to $\rm 150~keV$. In the absence of any cyclotron line in its energy spectrum, we estimate the magnetic field of the source based on the observed spin evolution of the neutron star by applying two accretion torque models. In both cases, we get consistent results with $B\rm \sim 10^{13}~G$, $D\rm \sim 6~kpc$ and peak luminosity of $\rm >10^{39}~erg~s^{-1}$ which makes the source the first Galactic ultraluminous X-ray source hosting a neutron star.Comment: publishe

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.0443

Kekonvergenan eksp0ektrasi variabel random dalam integral labesgue

Suatu variabel random dapat dinyatakan sebagai jumlahan fungsi sederhana. Selanjutnya ekspektasinya dapat dinyatakan dalam ekspektasi Integral Lebesgue sebagai limit ekspektasi barisan variabel random .Untuk mutlak dari yang lebih besar atau sama dengan n juga konvergen ke & maka ekspektasi dari mutlak berhingga, ekspektasi tn konvergen ke ekspektasi dan konvergensi tn terhadap dalam ekspektasi konvergen ke nol. This document is Undip. Institutional Repository Collection. The author(s) or copyright owner(s) agree that UNDIP-IR may, without changing the content, translate the submission to any medium or format for the purpose of preservation. The author(s) or copyright owner(s) also agree that UNDIP-IR may keep more than one copy of this submission for purpose of security, back-up and preservation: http://eprints.undipiSLid