Re: Reclaim regression after 1c30844d2dfe

From: Mel Gorman
Date: Wed Feb 12 2020 - 18:55:31 EST


On Wed, Feb 12, 2020 at 02:45:39PM -0800, Ivan Babrou wrote:
> Here's a typical graph: https://imgur.com/a/n03x5yH
>
> * Green (numa0) and blue (numa1) for 4.19
> * Yellow (numa0) and orange (numa1) for 5.4
>
> These downward slopes on numa0 on 5.4 are somewhat typical to the
> worst case scenario.
>
> If I try to clean up data a bit from a bunch of machines, this is how
> numa0 compares to numa1 with 1h average values of free memory above
> 5GiB:
>
> * https://imgur.com/a/6T4rRzi
>
> I think it's safe to say that numa0 is much much worse, but I cannot
> be 100% sure that numa1 is free from adverse effects, they may be just
> hiding in the noise caused by rolling reboots.
>

Ok, while I expected node 0 to be worse in general, a runaway boost due
to constant fragmentation would be a problem in general. In either case,
the patch should reduce the damage. Is there any chance that the patch
can be tested or would it be disruptive for you?

--
Mel Gorman
SUSE Labs