caching - How does Page Cache work in memory? Specifically in Linux -


as know, operating system implement page mechanism achieve fast access. every time, when process requests kernel load binary disk memory space, kernel first have @ page cache. if binaries cached in page cache, there no need access hardware disk. in way, os can reduce overhead.

however, have question.

as know, os page cache allocate pages in physical memory hold data potentially used soon. when process's requesting data discovered in page cache kernel, kernel pass process? kernel copy content of pagecache's page holding data in need new page allocated process? or kernel return pointer of page in pagecache?

there many operating systems out there, if we're talking arbitrary real, future or theoretical operating system answer "either".

however, real operating systems i'm aware of, page in memory once. inefficient create copy of each page, , doing not create benefit.


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