Re: [PATCH v1 1/2] Add the initify gcc plugin

Rasmus Villemoes
2016-06-28T21:06:07Z

On Tue, Jun 28 2016, Emese Revfy <re.emese@gmail.com> wrote:

> The kernel already has a mechanism to free up code and data memory that
> is only used during kernel or module initialization.
> This plugin will teach the compiler to find more such code and data that
> can be freed after initialization.
> It has two passes. The first one tries to find all functions that
> can be become __init/__exit. The second one moves string constants
> (local variables and function string arguments marked by
> the nocapture attribute) only referenced in __init/__exit functions
> to the __initconst/__exitconst sections.
> It reduces memory usage. This plugin can be useful for embedded systems.

May I suggest, as a followup patch, a debug option/plugin parameter to
put the strings in a section which will not be reaped after init, but
just marked inaccessible, with graceful handling of bad accesses (print
a big fat warning, make the page(s) readable, continue)?

Rasmus