Taylor Blau <me@xxxxxxxxxxxx> writes: >> > There is some overhead to invoke the hook and talk to watchman, but >> > I'd expect that to be dwarfed by not having to issue O(# files) >> > syscalls. >> >> "invoke the hook"---is that a pipe+fork+exec, or something else that >> is far lighter-weight? > > The former; see 'fsmonitor.c:query_fsmonitor()'. It brings us back to the "overhead of how many lstat(2) takes us closer to the overhead of a single pipe+fork+exec plus reading from the pipe", doesn't it?
