Re: [PATCH v2 0/5] introduce kcompactd and stop compacting in kswapd

[Vlastimil Babka]

On 03/09/2016 04:52 PM, Michal Hocko wrote:
> On Mon 08-02-16 14:38:06, Vlastimil Babka wrote:
> > The previous RFC is here [1]. It didn't have a cover letter, so the description
> > and results are in the individual patches.
>
> FWIW I think this is a step in the right direction. I would give my

Thanks!

> Acked-by to all patches but I wasn't able to find time for a deep review
> and my lack of knowledge of compaction details doesn't help much. I do
> agree that conflating kswapd with compaction didn't really work out well
> and fixing this would just make the code more complex and would more
> prone to new bugs.

Yeah, it seems that direct reclaim/compaction is complex enough already...

> In future we might want to invent something similar
> to watermarks and set an expected level of high order pages prepared for
> the allocation (e.g. have at least XMB of memory in order-9+). kcompact
> then could try as hard as possible to provide them. Does that sound at
> least doable?

Sure, that was/is part of the plan. But I was trimming the series for 
initial merge over the past year to arrive at a starting point where 
reaching consensus is easier.

> Thanks!