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Date: Thu, 9 May 2024 07:57:30 -0700
From: Roman Gushchin <roman.gushchin@linux.dev>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Muchun Song <muchun.song@linux.dev>,
	Michal Hocko <mhocko@kernel.org>,
	Shakeel Butt <shakeel.butt@linux.dev>,
	Matthew Wilcox <willy@infradead.org>, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH rfc 0/9] mm: memcg: separate legacy cgroup v1 code and
 put under config option
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References: <20240509034138.2207186-1-roman.gushchin@linux.dev>
 <20240509142205.GC374370@cmpxchg.org>
 <20240509143635.GD374370@cmpxchg.org>
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On Thu, May 09, 2024 at 10:36:35AM -0400, Johannes Weiner wrote:
> On Thu, May 09, 2024 at 10:22:10AM -0400, Johannes Weiner wrote:
> > On Wed, May 08, 2024 at 08:41:29PM -0700, Roman Gushchin wrote:
> > > 3) Is it better to use a new include/linux/memcontrol-v1.h instead of
> > >    mm/internal.h? Or mm/memcontrol-v1.h.
> > 
> > mm/memcontrol-v1.h sounds good to me.
> 
> Argh, there is a folio_memcg_lock() callsite in fs/buffer.c. I suppose
> include/linux/memcontrol-v1.h makes the most sense then.

You mean put everything into include/linux/memcontrol-v1.h?
And functions from memcontrol.c by memcontrol-v1.c into
include/linux/memcontrol.h?

It's an option I considered it but the downside is that we're "leaking"
a lot of internal definitions into the outside world, because
memcontrol.h is included everywhere.

So maybe mm/memcontrol-v1.h for definitions shared between v1 and v2
and keep exported functions in include/linux/memcontrol.h? There are
only few of them.

Thanks!