Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > End result: doing the fault_in_readable "unnecessarily" at the > beginning is likely the better optimization. It's basically free when > it's not necessary, and it avoids an extra fault (and extra > lock/unlock and retry) when it does end up faulting pages in. It may also cause the read in to happen in the background whilst write_begin is being done. David