Re: [PATCH 0/2] arm64 defconfig: Get faddr2line working

From: John Garry
Date: Mon Jul 25 2022 - 13:39:52 EST


On 25/07/2022 15:22, Arnd Bergmann wrote:
INTERCONNECT has no dependencies, so "select" - like for MAILBOX -
should be fine, I suppose
There are a couple of trade-offs between the two approaches.
The main advantage of 'select' is that you can enable drivers more
easily and all the required subsystems are there automatically.
The advantage of 'depends on' is that it becomes easier to disable
entire subsystems that one may not need.

Which of those two is more important is of course a matter of perspective,
I like to be able to turn things off more easily because that makes it
possible to test the corner cases with randconfig more easily, and it
helps produce size-reduced kernels for embedded systems.

Another aspect is that we overall have more 'depends on' than 'select',
and sticking with the more common way avoids circular dependencies,
both within an area of the kernel and overall.

The rule that I tend to follow with 'select' is to only use it on symbols
that you don't even want to show to users. If a feature is part of
a library (think zlib), then each user just needs to select the symbol
but you never actually have to decide whether to show it or not.

ok, seems reasonable. Personally I dislike 'select' for all the common reasons.


And would each config item deletion merit a separate patch?
You send a combined patch for the obvious ones (secccomp
and mailbox AFAICT) or send them separately. For the other ones I think
we should try fixing the Kconfig files first, otherwise we just end up
putting them back afterwards.
ok, fine. I'll deal with the obvious changes first plus
CONFIG_DEBUG_INFO and then the non-obvious, non-trivial ones. I'll base
on your arm/defconfig branch (for defconfig changes).
The CONFIG_DEBUG_INFO one should be fixed by my series from
last week already, do you still see another issue with that?

Ah, I thought that you re-enabled CONFIG_DEBUG_INFO for only the arm32 configs but see that you also re-enabled for arm64 defconfig as well.

I actually
have another patch to fix up all the non-Arm defconfigs for this one as
well, but haven't sent that one yet.

Thanks,
John