Re: [PATCH] mm/vmscan: don't scan adjust too much if current is not kswapd

[Mel Gorman]

On Tue, Sep 20, 2022 at 10:23:05AM +0800, Hongchen Zhang wrote:
> Hi Mel,
> 
> The scan adjust algorithm was originally introduced by you from
> commmit e82e0561dae9 ("mm: vmscan: obey proportional scanning requirements
> for kswapd"), any suggestion about this fix patch?
> In short, proportional scanning is not friendly to processes other than
> kswapd.
> 

I suspect that 6eb90d649537 ("mm: vmscan: fix extreme overreclaim and swap
floods") is a more appropriate fix. While it also has a fairness impact,
it's a more general approach that is likely more robust and while
fairness is important, completely thrashing a full LRU is neither fair
nor expected.

-- 
Mel Gorman
SUSE Labs