Shared Last-Level Caches and The Case for Longer Timeslices

ABSTRACT Memory performance is important in modern systems. Contention at various levels in memory hierarchy can lead to significant application performance degradation due to interference. Further, modern, large, last-level caches (LLC) have fill times greater than the OS scheduling window. When several threads are running concurrently and time-sharing the CPU cores, they may never be able to load their working sets into the cache before being rescheduled, thus permanently stuck in the "cold-start" regime. We show that by increasing the system scheduling timeslice length it is possible to amortize the cache cold-start penalty due to the multitasking and improve application performance by 10-15%

Numerical Method for Solving of the Anomalous Diffusion Equation Based on a Local Estimate of the Monte Carlo Method

This paper considers a method of stochastic solution to the anomalous diffusion equation with a fractional derivative with respect to both time and coordinates. To this end, the process of a random walk of a particle is considered, and a master equation describing the distribution of particles is obtained. It has been shown that in the asymptotics of large times, this process is described by the equation of anomalous diffusion, with a fractional derivative in both time and coordinates. The method has been proposed for local estimation of the solution to the anomalous diffusion equation based on the simulation of random walk trajectories of a particle. The advantage of the proposed method is the opportunity to estimate the solution directly at a given point. This excludes the systematic component of the error from the calculation results and allows constructing the solution as a smooth function of the coordinate

Investigation of terahertz radiation influence on rat glial cells

Abstract We studied an influence of continuous terahertz (THz) radiation (0.12–0.18 THz, average power density of 3.2 mW/cm²) on a rat glial cell line. A dose-dependent cytotoxic effect of THz radiation is demonstrated. After 1 minute of THz radiation exposure a relative number of apoptotic cells increased in 1.5 times, after 3 minutes it doubled. This result confirms the concept of biological hazard of intense THz radiation. Diagnostic applications of THz radiation can be restricted by the radiation power density and exposure time