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From: Nhat Pham <nphamcs@gmail.com>
Date: Wed, 31 Jan 2024 15:23:08 -0800
Message-ID: <CAKEwX=P6YqKzVMzZiTry8UafSFnpnvLxJekeP3B03oy3uDyg0w@mail.gmail.com>
Subject: Re: [PATCH 11/20] mm: zswap: function ordering: pool refcounting
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, Yosry Ahmed <yosryahmed@google.com>, 
	Chengming Zhou <zhouchengming@bytedance.com>, linux-mm@kvack.org, 
	linux-kernel@vger.kernel.org
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On Wed, Jan 31, 2024 at 3:23=E2=80=AFAM Johannes Weiner <hannes@cmpxchg.org=
> wrote:
>
> On Tue, Jan 30, 2024 at 12:13:30PM -0800, Nhat Pham wrote:
> > On Mon, Jan 29, 2024 at 5:42=E2=80=AFPM Johannes Weiner <hannes@cmpxchg=
org> wrote:
> > >
> > > Move pool refcounting functions into the pool section. First the
> > > destroy functions, then the get and put which uses them.
> > >
> > > __zswap_pool_empty() has an upward reference to the global
> > > zswap_pools, to sanity check it's not the currently active pool that'=
s
> > > being freed. That gets the forward decl for zswap_pool_cuyrrent().
> >
> > nit: zswap_pool_cuyrrent() -> zswap_pool_current() :-)
>
> Whoops, my bad.
>
> Andrew, would you mind removing that typo inside your copy?
>
> > Also, would it make sense to move zswap_pool_current() above
> > __zswap_pool_empty() to get rid of the forward declaration? I guess
> > it's now grouped with current_get() etc. - those don't seem to use the
> > empty check, so maybe they can also go above __zswap_pool_empty()?
>
> There is a grouping to these functions:
>
> - low-level functions that create and destroy individual struct zswap_poo=
l
>   (create, destroy, get, release, empty, put)
> - high-level functions that operate on pool collections, i.e. zswap_pools
>   (current, last, find)
>
> They were actually already grouped like that, just in the reverse
> order. The only way to avoid ALL forward decls would be to interleave
> the layers, but I think the grouping makes sense so I wanted to
> preserve that. I went with low to high ordering, and forward decl the
> odd one where a low-level function does one high-level sanity check.
>
> Does that make sense?

Makes sense to me - just double checking :)
Reviewed-by: Nhat Pham <nphamcs@gmail.com>