Re: [PATCH v4 0/3] Ignore non-LRU-based reclaim in memcg reclaim

[Andrew Morton]

On Tue, 4 Apr 2023 16:46:30 -0700 Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote:

> > But the key question remains: how desirable is a backport?
> >
> > Looking at the changelogs I'm not seeing a clear statement of the
> > impact upon real-world users' real-world workloads.  (This is a hint).
> > So I am unable to judge.
> >
> > Please share your thoughts on this.
> 
> I think it's nice to have but not really important. It occasionally
> causes writes to memory.reclaim to report false positives and *might*
> cause unnecessary retrying when charging memory, but probably too rare
> to be a practical problem.
> 
> Personally, I intend to backport to our kernel at Google because it's
> a simple enough fix and we have occasionally seen test flakiness
> without it.
> 
> I have a reworked version of the series that only has 2 patches:
> - simple-two-liner-patch (actually 5 lines)
> - one patch including all refactoring squashed (introducing
> flush_reclaim_state() with the huge comment, introducing
> mm_account_reclaimed_pages(), and moving set_task_reclaim_state()
> around).
> 
> Let me know if you want me to send it as v5, or leave the current v4
> if you think backporting is not generally important.

Let's have a look at that v5 and see what people think?