Re: [PATCH] mm: Make mem_cgroup_id_get_many dependent on MMU and MEMCG_SWAP

[Chris Down <chris@chrisdown.name>]

Johannes Weiner writes:
>I would ack a patch that adds __maybe_unused.
>
>This is a tiny function. If we keep it around a few releases after
>removing the last user, it costs us absolutely nothing. Eventually
>somebody will notice and send a patch to remove it. No big deal.
>
>There is, however, real cost in keeping bogus warnings around and
>telling people to ignore them. It's actively lowering the
>signal-to-noise ratio and normalizing warnings to developers. That's
>the kind of thing that will actually hide problems in the kernel.
>
>We know that the function can be unused in certain scenarios. It's
>silly to let the compiler continue to warn about it. That's exactly
>what __maybe_unused is for, so let's use it here.

Yeah, this is exactly what I was trying to express in the first one[0]. The 
fact that this patch came around a second time, as expected, just solidifies my 
concern around the waste to human time.

I would also ack a patch that adds __maybe_unused.

0: https://lore.kernel.org/linux-mm/20191217143720.GB131030@chrisdown.name/