Re: [PATCH] mm: skip current when memcg reclaim

[Michal Hocko]

On Wed 20-10-21 15:33:39, Zhaoyang Huang wrote:
[...]
> Do you mean that direct reclaim should succeed for the first round
> reclaim within which memcg get protected by memory.low and would NOT
> retry by setting memcg_low_reclaim to true?

Yes, this is the semantic of low limit protection in the upstream
kernel. Have a look at do_try_to_free_pages and how it sets
memcg_low_reclaim only if there were no pages reclaimed.

> It is not true in android
> like system, where reclaim always failed and introduce lmk and even
> OOM.

I am not familiar with android specific changes to the upstream reclaim
logic. You should be investigating why the reclaim couldn't make a
forward progress (aka reclaim pages) from non-protected memcgs. There
are tracepoints you can use (generally vmscan prefix).

-- 
Michal Hocko
SUSE Labs