linux 下看cpuinfo clflush size什么意思

clfush in the features list refers to the availability of the cache-line flushing feature, an instruction to tell the CPU's cache that a particular block of data is no longer needed or perhaps no longer valid (so should be re-read from elsewhere if needed). I'm guessing that the size specified in clflush size would be the granularity with which this process can be controlled - i.e. the smallest block that can be flushed (probably related directly to the line width of the CPU's L1 caches). This too is probably not a useful thing to know, unless you are a CPU engineer or otherwise trying to debug something at a very very low level.