Date:   Tue, 7 Dec 2021 15:21:24 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Arnd Bergmann <arnd@kernel.org>
Cc:     linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        Guenter Roeck <groeck@chromium.org>,
        Kees Cook <keescook@chromium.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        kernel test robot <lkp@intel.com>,
        Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Will Deacon <will@kernel.org>,
        Waiman Long <longman@redhat.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tejun Heo <tj@kernel.org>, kernelci@groups.io,
        linux-fsdevel@vger.kernel.org, linux-kbuild@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [RFC 1/3] headers: add more types to linux/types.h
Message-ID: <Ya979Hh0V2CdhNSU@casper.infradead.org>
References: <20211207150927.3042197-1-arnd@kernel.org>
 <20211207150927.3042197-2-arnd@kernel.org>
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On Tue, Dec 07, 2021 at 04:09:25PM +0100, Arnd Bergmann wrote:
> +struct list_lru {
> +	struct list_lru_node	*node;
> +#ifdef CONFIG_MEMCG_KMEM
> +	struct list_head	list;
> +	int			shrinker_id;
> +	bool			memcg_aware;
> +#endif
> +};

This is the only one that gives me qualms.  While there are other
CONFIG options mentioned in types.h they're properties of the platform,
eg CONFIG_HAVE_UID16, CONFIG_64BIT, CONFIG_ARCH_DMA_ADDR_T_64BIT, etc.
I dislike it that changing this CONFIG option is going to result in
rebuilding the _entire_ kernel.  CONFIG_MEMCG_KMEM just isn't that
central to how everything works.