Christian Weisgerber <[email protected]> wrote: > On 2019-08-16, Jan Stary <[email protected]> wrote: > > >> Does that mean openrsync tries to mmap() the entire file? > >> The machine only has 256MB of memory, but it does transfer > >> a test file of 300MB, so that can't be it. > > > > I forgot about 1GB swap, so that's why it works > > for files up to around 1.2G, but not larger. > > Why would the size of physical memory + swap matter? > mmap() doesn't copy a file into memory, it maps it into the address > space.
Yes, but when rsync calculates the hash, before exchanging the hash to decide if it should ship the file, it touches every page of the file, which pulls it into the process.........
