Re: [RFC PATCH] mm: net: disable kswapd for high-order network buffer allocation

[Michal Hocko <mhocko@suse.com>]

On Mon 13-10-25 15:46:54, Roman Gushchin wrote:
> Vlastimil Babka <vbabka@suse.cz> writes:
> 
> > On 10/13/25 12:16, Barry Song wrote:
[...]
> >> An alternative approach is to disable kswapd for these frequent
> >> allocations and provide best-effort order-3 service for both TX and RX paths,
> >> while removing the sysctl entirely.
> 
> I'm not sure this is the right path long-term. There are significant
> benefits associated with using larger pages, so making the kernel fall
> back to order-0 pages easier and sooner feels wrong, tbh. Without kswapd
> trying to defragment memory, the only other option is to force tasks
> into the direct compaction and it's known to be problematic.
> 
> I wonder if instead we should look into optimizing kswapd to be less
> power-hungry?

Exactly. If your specific needs prefer low power consumption to higher
order pages availability then we should have more flixible way to say
that than a hardcoded allocation mode. We should be able to tell
kswapd/kcompactd how much to try for those allocations.
-- 
Michal Hocko
SUSE Labs