Question：Why the mmap() function needs to use the MAP_SYNC flag?

[luchao2424631502]

Hello developer, I have a very basic question about why the mmap() function needs to use the MAP_SYNC flag? I have consulted the man manual, and it says that it is necessary to combine CPU instructions to achieve persistent modification of data. Does this mean that the mapped memory bypasses PageCache? I hope to receive your answer.

perma-bench/src/utils.hpp

Line 27 in 7c8cc3a

static int PMEM_MAP_FLAGS = MAP_SHARED_VALIDATE | MAP_SYNC;