答案是CPU 内部一个叫 "WC buffer" 的硬件单元,它不是 L1/L2/L3 cache,也不是 store buffer。 参考: AMD64 Architecture Programmer's Manual Volume 2 第7.4 节 Memory Types Armv8-A memory model Understanding Write Combining on Arm developer.arm.com/docum Semantics of MMIO mapping attributes ...
因此,为了进一步减小延迟的影响,一些鲜为人知的缓冲区派上了用场。 本文将探讨“合并写存储缓冲区(write combining store buffers)”,以及如何写出有效利用它们的代码。 CPU缓存是一种高效的非链式结构的hash map,每个桶(bucket)通常是64个字节。这就是一个“缓存行(cache line)”。缓存行是内存交换的实际单位。例...
system forces the CPU to remove the cache linefromits cache. 2) The CPUisallowed to write the contentsfromits cache back to memory at any pointintime, evenifthe program will never actually write to the cacheline; the lateristhe result of speculation etc; what will be written inthatcaseis...
A method and apparatus for performing non-temporal write combining using existing cache resources is disclosed. In one embodiment, a method includes executing a first thread on a processor core, the first thread including a first block initialization store (BIS) instruction. A cache query may be ...
1) The CPU is allowed to read the data from the memory into its cache at any point in time, even if the program will never actually read the memory. Hardware prefetching, speculative execution etc etc all can cause the cpu to get content into its caches if it's cachable. The CPU is...
where cached memory accesses waste external bus bandwidth on cache line fills, when most accesses are writes. The write combining technique involves the use of a write combining protocol which maintains coherency with external writes, but avoids the penalty of coherence by deferring the coherence ...
Applications that have a requirement for write-behind caching but which must avoid write-combining (for example, for auditing reasons), should create a "versioned" cache key (for example, by combining the natural primary key with a sequence id). ...
I have a question about write-combining. In the case of write-combinging(mapping with remap_pfn_range and pgprot_writecombine), CPU may buffer several writes within cache-aligned 64 bytes and then do a single real write. How does the CPU d...
Twitter Google Share on Facebook WCE (redirected fromWrite Cache Enable) Category filter: AcronymDefinition WCEWest Coast Eagles(Australia) WCEWallace(Amtrak station code; Wallace, NC) WCEWoman Crush Everyday WCEWest Coast Express(commuter rail system; Canada) ...
网络写组合缓冲;写组合缓存 网络释义