Re: [For Stable] mm: memcontrol: fix excessive complexity in memory.stat reporting

[Greg KH <gregkh@linuxfoundation.org>]

A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

A: No.
Q: Should I include quotations after my reply?

http://daringfireball.net/2007/07/on_top

On Wed, Apr 24, 2019 at 10:35:51AM -0700, Vaibhav Rustagi wrote:
> Apologies for sending a non-plain text e-mail previously.
> 
> This issue is encountered in the actual production environment by our
> customers where they are constantly creating containers
> and tearing them down (using kubernetes for the workload).  Kubernetes
> constantly reads the memory.stat file for accounting memory
> information and over time (around a week) the memcg's got accumulated
> and the response time for reading memory.stat increases and
> customer applications get affected.

Please define "affected".  Their apps still run properly, so all should
be fine, it would be kubernetes that sees the slowdowns, not the
application.  How exactly does this show up to an end-user?

> The repro steps mentioned previously was just used for testing the
> patches locally.
> 
> Yes, we are moving to 4.19 but are also supporting 4.14 till Jan 2020
> (so production environment will still contain 4.14 kernel)

If you are already moving to 4.19, this seems like a good as reason as
any (hint, I can give you more) to move off of 4.14 at this point in
time.  There's no real need to keep 4.14 around, given that you don't
have any out-of-tree code in your kernels, so all should be simple to
just update the next reboot, right?

thanks,

greg k-h