On Thu, Feb 17, 2005 at 03:38:05PM -0800, Stephen Williams wrote: > My embedded system is structured such that the main user-mode > processes that are being run are downloaded and executed on demand. > I'm currently downloading the executable to an ext3 system on the > CompactFlash, but there is really no reason to use non-volatile > memory so I'm thinking to download to a tempfs directory and > execute from there. > > But if I do that, I want to remove the program from the directory > after I start it, so that the file does not take up ram space. Will > that actually work? I'm using exec(2) to execute the program file > wherever it is downloaded. Will a subsequent unlink of the file > have a result, or will the file continue to take up space as > backing store for the executable?
I think unlink will remove the file from directory (so you won't be able to see it with ls), but it will still continue to to take space - you're right it will be used as backing store, at least for read-only segments, which can be discarded if memory is tight. Even if you mlock all executable in memory, I think there will be still at least one reference to this file, which will prevent freeing tmpfs memory. -- Eugene
