Re: [PATCH v6 0/7] fs/dcache: Track & limit # of negative dentries

From: Michal Hocko
Date: Mon Jul 16 2018 - 05:12:28 EST


On Mon 16-07-18 11:09:01, Michal Hocko wrote:
> On Fri 13-07-18 10:36:14, Dave Chinner wrote:
> [...]
> > By limiting the number of negative dentries in this case, internal
> > slab fragmentation is reduced such that reclaim cost never gets out
> > of control. While it appears to "fix" the symptoms, it doesn't
> > address the underlying problem. It is a partial solution at best but
> > at worst it's another opaque knob that nobody knows how or when to
> > tune.
>
> Would it help to put all the negative dentries into its own slab cache?

We couldn't http://lkml.kernel.org/r/20180714173516.uumlhs4wgfgrlc32@devuan
Sorry I haven't noticed the other line of discussion
--
Michal Hocko
SUSE Labs