Re: negative dentries wasting ram

Linus Torvalds
2002-05-24T16:29:52Z

On Fri, 24 May 2002, Alexander Viro wrote:
>
> On Fri, 24 May 2002, Linus Torvalds wrote:
>
> > However, you're right that it probably doesn't help to do this after
> > "unlink()" - it's probably only worth doing when actually doing a
> > "lookup()" that fails.
>
> Depends on many things, including the amount of userland code that does
> unlink(name);
> open(name, O_CREAT|O_EXCL..., ...);

Note that this will have to touch the FS anyway, since the O_CREAT thing
forces a call down to the FS to actually create the file.

The only think we save is a dentry kfree/kmalloc in this case, nbot a FS
downcall. And I think Andrea is right that it can waste memory for the
likely much more common case where the file just stays removed.

Linus