Re: negative dentries wasting ram

[Eric W. Biederman]

Andrea Arcangeli <[e-mail]> writes:
> 
> Anyways in 2.5 we could still take advantage of the negative dentries as
> much as possible (also after unlink) by moving the negative dentries
> into a separate list and by putting the shrinkage of this list in front
> of kmem_cache_reap, so we are as efficient as possible, but we don't
> risk throwing away very useful cache, for more dubious caching effects
> after an unlink/create-failure that currently have the side effect of
> throwing away tons of worthwhile positive pagecache (and even triggering
> swap false positives) in some workloads.

Right treat the new never referenced negative dentries as second class
citizens until someone comes along and uses them, instead of aged useful
cache entries.  This sounds like a very good solution to this.

Eric