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 de
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 ...
3) The CPU is allowed to write a full cacheline without having read it; it will just get the cacheline exclusive in this case. 4) The CPU is allowed to hold on to written cache lines without writing them back for as long as it wants, until something in the cache coherency protocol ...
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 decide...
writecache cvol (fast) volume using the same slow device lvcreate --yes -L 2G -n POOL writecache_sanity /dev/sdh1 Deactivate *ONLY* fast pool before conversion to write cache (SEE bug 1185347) Create writecached volume by combining the cache pool (fast) and origin (slow) volumes ...
网络写组合缓冲;写组合缓存 网络释义
Write CombiningforLinear Frame Buffer(s) exposed by PCI/AGP graphics cards and VESA BIOS(auto detected) L1 CachetoEnabled L2 CachetoEnabled(supported CPUs only!) Data PrefetchtoEnabled This can be altered and overridden with many command line parameters. ...