Re: [PATCH V2] nommu: add anonymous page memcg accounting

From: KAMEZAWA Hiroyuki
Date: Wed Oct 20 2010 - 22:48:11 EST


On Wed, 20 Oct 2010 21:35:16 -0500
"Steve Magnani" <steve@xxxxxxxxxxxxxxx> wrote:

> On Thu, 2010-10-21 at 09:08 +0900, KAMEZAWA Hiroyuki wrote:
> > I myself can't maintain NOMMU kernel. So, please test every -rc1 when
> > this patch merged. OK ?
>
> It's reasonable to ask that features be tested every so often, and since the memory cgroup code seems to be
> changing relatively frequently it probably needs exercising more often. I can't commit to this, though - I
> don't know how much longer I'll be working with NOMMU kernels, and they are notoriously fragile. Any memory
> access bug that would cause an oops (or SEGV) in a "normal" kernel can cause subtle and almost impossible to
> debug behavior on a NOMMU system. For this reason I always try to work with "stable" kernels (recent threads
> debating the term notwithstanding)...so it would be a pretty far jump to a -rc1 kernel.
>
> Is this a showstopper (in which case David's patch to make the CGROUP_MEM_RES_CTLR Kconfig option depend on MMU
> should be implemented), or should I post V3 of the patch that has Balbir's suggested change?
>

I asked just because I'm curious and maintainance is always a concern.
But it's not showstopper.

BTW, my request is updating Documentaion as:

1. Please clarify "When reaching limit, OOM-Kill is inoved."
2. Add TODO List.
For example)For NOMMU guys, you don't need page_cgroup->lru because no page reclaim happens.
I think you can delete page_cgroup->lru and save much memmory.

I'll ack if v3 seems O.K. But I'm sorry it's in merge-window and people will be busy
for a while. please be patient.

Thanks,
-Kame

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