Word of the Day: translation lookaside buffer (TLB)

Word of the Day Daily updates on the latest technology terms | October 10, 2018 translation lookaside buffer (TLB) A translation lookaside buffer (TLB) is a memory cache that stores recent translations of virtual memory to physical addresses for faster retrieval. When a virtual memory address is referenced by a program, the search starts in the CPU. First, instruction caches are checked. If the required memory is not in these very fast caches, the system has to look up the memory's physical address. At this point, TLB is checked for a quick reference to the location in physical memory. When an address is searched in the TLB and not found, the physical memory must be searched with a memory page crawl operation. As virtual memory addresses are translated, values referenced are added to TLB. When a value can be retrieved from TLB, speed is enhanced because the memory address is stored in the TLB on processor. Most processors include TLBs to increase the speed of virtual memory operations through the inherent latency-reducing proximity as well as the high-running frequencies of current CPU's. TLBs also add the support required for multi-user computers to keep memory separate, by having a user and a supervisor mode as well as using permissions on read and write bits to enable sharing. TLBs can suffer performance issues from multitasking and code errors. This performance degradation is called a cache thrash. Cache thrash is caused by an ongoing computer activity that fails to progress due to excessive use of resources or conflicts in the caching system. Quote of the Day "TLB-splitting segregates the portion of a computer's memory where a program stores its data from the portion where it stores its own code's instructions." - Michael Cobb Trending Terms virtual memory cache thrash second-level address translation physical to virtual hypervisor cache Learning Center How does TLBleed abuse the Hyper-Threading feature in Intel chips? TLBleed exploits use Intel's HTT feature to leak data. Learn how hackers could use this new side-channel attack to obtain sensitive memory information. TLBleed attack can extract signing keys, but exploit is difficult Researchers discovered a side-channel attack, named TLBleed, that abuses the Hyper-Threading feature of Intel chips. But Intel said customers should be immune, even without a patch. Virtualization isn't perfect, but SLAT minimizes hypervisor overhead Second Level Address Translation can help reduce hypervisor overhead, but you may need to check for SLAT support on existing systems and enable support in the BIOS. CPU features you need for virtualization CPU features are critical to hypervisor performance. Choosing the right hardware can ensure your virtualized workloads run at peak performance. Can a new encryption trick prevent reverse engineering? Learn about Hardened Anti-Reverse Engineering System, or HARES, which cannot exactly prevent reverse engineering, but makes it a little tougher for attackers to complete. Quiz Yourself There are three major areas of __________ network virtualization, storage virtualization and server virtualization. a. virtualization; b. virtualization: Answer Stay in Touch For feedback about any of our definitions or to suggest a new definition, please contact me at: mrouse@techtarget.com Visit the Word of the Day Archives and catch up on what you've missed! FOLLOW US About This E-Newsletter This e-newsletter is published by the TechTarget network. To unsubscribe from Whatis.com, click here. Please note, this will not affect any other subscriptions you have signed up for. TechTarget, Whatis, 275 Grove Street, Newton, MA 02466. Contact: webmaster@techtarget.com Copyright 2018 TechTarget. All rights reserved.