Re: [PATCH 2/4] selftests: memcg: Expect no low events in unprotected sibling
From: Michal Koutný
Date: Wed May 18 2022 - 11:55:01 EST
Hi.
On Fri, May 13, 2022 at 11:54:16AM -0700, Roman Gushchin <roman.gushchin@xxxxxxxxx> wrote:
> Hm, what are our plans here? Are we going to fix it soon-ish, or there
> is still no agreement on how to proceed?
Here are some of my ideas in random order so far and comments:
0) mask memory.events:low
-> not a real fix
1) don't do SWAP_CLUSTER_MAX roundup
-> won't solve sudden lift of protection
2) instead of SWAP_CLUSTER_MAX over-reclaim, do same under-reclaim
-> same problem as 1)
3) update children_low_usage transactionally (after reclaim round is done)
- ???
4) don't recursively distribute residual protection in the same reclaim round
- ???
5) iterate siblings from highest to lowest protection
- not a solution
6) assign only >SWAP_CLUSTER_MAX of residuum
- need more info
I'm discouraged by possible complexity of 3) or 4), while 6) is what I'd
like to look more into.
HTH,
Michal