[PATCH v6 6/9] mm: multigenerational lru: aging

[Michal Hocko]

On Fri 07-01-22 09:55:09, Michal Hocko wrote:
[...]
> > In this case, lru_gen_mm_walk is small (160 bytes); it's per direct
> > reclaimer; and direct reclaimers rarely come here, i.e., only when
> > kswapd can't keep up in terms of the aging, which is similar to the
> > condition where the inactive list is empty for the active/inactive
> > lru.
> 
> Well, this is not a strong argument to be honest. Kswapd being stuck
> and the majority of the reclaim being done in the direct reclaim
> context is a situation I have seen many many times.

Also do not forget that memcg reclaim is effectivelly only direct
reclaim. Not that the memcg reclaim indicates a global memory shortage
but it can add up and race with the global reclaim as well.

-- 
Michal Hocko
SUSE Labs