Latency (engineering)

About: Latency (engineering) is a research topic. Over the lifetime, 7278 publications have been published within this topic receiving 115409 citations. The topic is also known as: lag.

A new approach to latency insensitive design

Abstract: Latency Insensitive Protocols have been proposed as a viable mean to speed up large Systems-on-Chip where the limit in clock frequency is given by long global wires connecting together functional blocks. In this paper we keep the philosophy of Latency Insensitive Design and show that a drastic simplification can be done that results in even no need to implement any kind of protocol. By using a scheduling algorithm for the functional blocks activation we greatly reduce the routing resources demand of the old protocol, the area occupied by the sequential elements used to pipeline long interconnects and the complexity of the gating structure used to activate the modules.

ParaBox: Exploiting Parallelism for Virtual Network Functions in Service Chaining

Abstract: Service Function Chains (SFCs) comprise a sequence of Network Functions (NFs) that are typically traversed in-order by data flows. Consequently, SFC delay grows linearly with the length of the SFC. Yet, for highly latency sensitive applications, this delay may be unacceptable---particularly when the constituent NFs are virtualized, running on commodity servers. In this paper, we investigate how SFC latency may be reduced by exploiting opportunities for parallel packet processing across NFs. We propose ParaBox, a novel hybrid packet processing architecture that, when possible, dynamically distributes packets to VNFs in parallel and merges their outputs intelligently to ensure the preservation of correct sequential processing semantics. To demonstrate the feasibility of our approach, we implement a ParaBox prototype on top of the DPDK-enabled Berkeley Extensible Software Switch. Our preliminary experiment results show that ParaBox can not only significantly reduce the service chaining latency, but also improve throughput.

Gamma Interferon Blocks Gammaherpesvirus Reactivation from Latency

Abstract: Establishment of latent infection and reactivation from latency are critical aspects of herpesvirus infection and pathogenesis. Interfering with either of these steps in the herpesvirus life cycle may offer a novel strategy for controlling herpesvirus infection and associated disease pathogenesis. Prior studies show that mice deficient in gamma interferon (IFN-γ) or the IFN-γ receptor have elevated numbers of cells reactivating from murine gammaherpesvirus 68 (γHV68) latency, produce infectious virus after the establishment of latency, and develop large-vessel vasculitis. Here, we demonstrate that IFN-γ is a powerful inhibitor of reactivation of γHV68 from latency in tissue culture. In vivo, IFN-γ controls viral gene expression during latency. Importantly, depletion of IFN-γ in latently infected mice results in an increased frequency of cells reactivating virus. This demonstrates that IFN-γ is important for immune surveillance that limits reactivation of γHV68 from latency.

Performance analysis and optimization of latency insensitive systems

Abstract: Latency insensitive design has been recently proposed in literature as a way to design complex digital systems, whose functional behavior is robust with respect to arbitrary variations in interconnect latency. However, this approach does not guarantee the same robustness for the performance of the design, which indeed can experience big losses. This paper presents a simple, yet rigorous, method to (1) model the key properties of a latency insensitive system, (2) analyze the impact of interconnect latency on the overall throughput, and (3) optimize the performance of the final implementation.

Differential γ-Herpesvirus Distribution in Distinct Anatomical Locations and Cell Subsets During Persistent Infection in Mice

Abstract: Murine γ-herpesvirus 68 (MHV-68) provides an important experimental model for analyzing γ-herpesvirus latent infection. After intranasal infection with MHV-68, we analyzed the distribution of the virus in different anatomical locations and purified populations of cells. Our data show that long-term latency is maintained in a variety of anatomical locations and cell populations with different frequencies. Importantly, we demonstrate that although latency in the lung is established in a variety of cell subsets, long-term latency in the lung is only maintained in B cells. In contrast, splenic latency is maintained in macrophages and dendritic cells, as well as in B cells. In blood, isotype-switched B cells constitute the major viral reservoir. These results show that the cell subsets in which latency is established vary within different anatomical sites. Finally, we demonstrate that long-term latency is accompanied by a low level of infectious virus in lung and spleen. These data have important implications for understanding the establishment and maintenance of latency by γ 2 -herpesviruses.