Search results
Results from the WOW.Com Content Network
Cache hierarchy, or multi-level cache, is a memory architecture that uses a hierarchy of memory stores based on varying access speeds to cache data. Highly requested data is cached in high-speed access memory stores, allowing swifter access by central processing unit (CPU) cores.
Consider the case when L2 is exclusive of L1. Suppose there is a processor read request for block X. If the block is found in L1 cache, then the data is read from L1 cache and returned to the processor. If the block is not found in the L1 cache, but present in the L2 cache, then the cache block is moved from the L2 cache to the L1 cache.
The unified page cache operates on units of the smallest page size supported by the CPU (4 KiB in ARMv8, x86 and x86-64) with some pages of the next larger size (2 MiB in x86-64) called "huge pages" by Linux. The pages in the page cache are divided in an "active" set and an "inactive" set. Both sets keep a LRU list of pages.
An optimal cache-oblivious algorithm is a cache-oblivious algorithm that uses the cache optimally (in an asymptotic sense, ignoring constant factors). Thus, a cache-oblivious algorithm is designed to perform well, without modification, on multiple machines with different cache sizes, or for a memory hierarchy with different levels of cache ...
Set-associative cache is a trade-off between direct-mapped cache and fully associative cache. A set-associative cache can be imagined as a n × m matrix. The cache is divided into ‘n’ sets and each set contains ‘m’ cache lines. A memory block is first mapped onto a set and then placed into any cache line of the set.
In computing, a memory access pattern or IO access pattern is the pattern with which a system or program reads and writes memory on secondary storage.These patterns differ in the level of locality of reference and drastically affect cache performance, [1] and also have implications for the approach to parallelism [2] [3] and distribution of workload in shared memory systems. [4]
Cache coherence is the discipline which ensures that the changes in the values of shared operands (data) are propagated throughout the system in a timely fashion. [2] The following are the requirements for cache coherence: [3] Write Propagation Changes to the data in any cache must be propagated to other copies (of that cache line) in the peer ...
– The cache is set M (D) if the "shared line" is off, otherwise is set O (SD). All the other copies are set S (V) Cache in E (R) or M (D) state (exclusiveness) – The write can take place locally without any other action. The state is set (or remains) M (D) Write Miss – Write Allocate – Read with Intent to Modified operation