Re: [PATCH 0/3] phy: remove needless usage of module header

From: Kishon Vijay Abraham I
Date: Mon Feb 04 2019 - 04:56:38 EST




On 10/12/18 6:04 AM, Paul Gortmaker wrote:
> The most important thing to note here, is these clean-ups make no
> changes to the final generated run-time. The 1st commit removes an
> unused function, otherwise the generated objects are also unchanged.
>
> The work here represents a scan over the phy dir, looking for files
> that have nothing to do with a modular use case, but are using modular
> infrastructure regardless.
>
> We are trying to make driver code consistent with the Makefiles/Kconfigs
> that control them. This means not using modular functions/macros for
> drivers that can never be built as a module. This has been done in quite
> a lot of other mainline subsystem dirs already.
>
> Using modular infrastructure in non-modules might seem harmless, but some
> of the downfalls this leads to are:
>
> (1) it is easy to accidentally write unused module_exit and remove code
> (2) it can be misleading when reading the source, thinking it can be
> modular when the Makefile and/or Kconfig prohibit it
> (3) it requires the include of the module.h header file which in turn
> includes nearly everything else, thus adding to CPP overhead.
> (4) it gets copied/replicated into other drivers and spreads quickly.
>
> As a data point for #3 above, an empty C file that just includes the
> module.h header generates over 750kB of CPP output. Repeating the same
> experiment with init.h and the result is less than 12kB; with export.h
> it is only about 1/2kB; with both it still is less than 12kB.
>
> Build tested on x86-64 and ARM-64.

merged, thanks!

-Kishon
>
> Paul.
> ---
>
> Cc: Andrew Lunn <andrew@xxxxxxx>
> Cc: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> Cc: Kishon Vijay Abraham I <kishon@xxxxxx>
>
> Paul Gortmaker (3):
> phy: make phy-core explicitly non-modular
> phy: make phy-mvebu-sata explicitly non-modular
> phy: make phy-armada375-usb2 explicitly non-modular
>
> drivers/phy/marvell/phy-armada375-usb2.c | 8 +-------
> drivers/phy/marvell/phy-mvebu-sata.c | 9 ++-------
> drivers/phy/phy-core.c | 12 +-----------
> 3 files changed, 4 insertions(+), 25 deletions(-)
>