Re: [PATCH 3/3] mm: oom: show unreclaimable slab info when unreclaimable slabs > user memory

[Michal Hocko]

On Tue 17-10-17 15:39:08, David Rientjes wrote:
> On Wed, 18 Oct 2017, Yang Shi wrote:
> 
> > > Yes, this should catch occurrences of "huge unreclaimable slabs", right?
> > 
> > Yes, it sounds so. Although single "huge" unreclaimable slab might not result
> > in excessive slabs use in a whole, but this would help to filter out "small"
> > unreclaimable slab.
> > 
> 
> Keep in mind this is regardless of SLAB_RECLAIM_ACCOUNT: your patch has 
> value beyond only unreclaimable slab, it can also be used to show 
> instances where the oom killer was invoked without properly reclaiming 
> slab.  If the total footprint of a slab cache exceeds 5%, I think a line 
> should be emitted unconditionally to the kernel log.

agreed. I am not sure 5% is the greatest fit but we can tune that later.

-- 
Michal Hocko
SUSE Labs