From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Down Subject: Re: [PATCH] mm: memcontrol.c: move mem_cgroup_id_get_many under CONFIG_MMU Date: Tue, 17 Dec 2019 15:09:21 +0000 Message-ID: <20191217150921.GA136178@chrisdown.name> References: <20191217135440.GB58496@chrisdown.name> <392D7C59-5538-4A9B-8974-DB0B64880C2C@lca.pw> <20191217144652.GA7272@dhcp22.suse.cz> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=uRifrYHkApcXnKzKR9sZGrhWwRmDmhE0ikbPGadvDHM=; b=crKI2MrdTHir1/QxP/Gc2TF/K5LQOSpYr8URTRvZSMKKZd2IgIojFD0O83S/Bq7wBT yjLxMTafYMdzf3fF/MvlxezrtHOD813wOAA/PfVag2ndv+LWndeMEvvqrBl174t8ahcL v1msU5U/qfNvNJUvqwR/V3PDAfi2JdKH0xG5U= Content-Disposition: inline In-Reply-To: <20191217144652.GA7272@dhcp22.suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" Content-Transfer-Encoding: 7bit To: Michal Hocko Cc: Qian Cai , Kuninori Morimoto , Johannes Weiner , Vladimir Davydov , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Michal Hocko writes: >yes, I would just ignore this warning. Btw. it seems that this is >enabled by default for -Wall. Is this useful for kernel builds at >all? Does it realistically help discovering real issues? If not then >can we simply blacklist it? There's no way we're the first people to encounter these problems, so what did we do in the past when situations like this (adding a generic API which is not yet used by non-configurable code) came up, and in retrospect did they work well? As far as I know -Wunused-function also guards against other errors, like when a function is prototyped but not actually defined, which might be more useful to know about. (Side note: I'm moderately baffled that a tightly scoped __maybe_unused is considered sinister but somehow disabling -Wunused-function is on the table :-))