linux-kernel - Re: [PATCH] mm: memcontrol: fix kernel stack account

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Date:   Tue, 2 Mar 2021 20:33:20 +0100
From:   Michal Hocko <mhocko@...e.com>
To:     Roman Gushchin <guro@...com>
Cc:     Muchun Song <songmuchun@...edance.com>, hannes@...xchg.org,
        akpm@...ux-foundation.org, shakeelb@...gle.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH] mm: memcontrol: fix kernel stack account

On Tue 02-03-21 10:50:32, Roman Gushchin wrote:
> On Tue, Mar 02, 2021 at 03:37:33PM +0800, Muchun Song wrote:
> > The alloc_thread_stack_node() cannot guarantee that allocated stack pages
> > are in the same node when CONFIG_VMAP_STACK. Because we do not specify
> > __GFP_THISNODE to __vmalloc_node_range(). Fix it by caling
> > mod_lruvec_page_state() for each page one by one.
> 
> Hm, I actually wonder if it makes any sense to split the stack over multiple
> nodes? Maybe we should fix this instead?

While this is not really ideal I am not really sure it is an actual
problem worth complicating the code. I am pretty sure this would grow
into more tricky problem quite quickly (e.g. proper memory policy
handling).
-- 
Michal Hocko
SUSE Labs