Re: [PATCH][RFC] mm: swsusp shrink_all_memory tweaks

[Con Kolivas <kernel@kolivas.org>]

cc'ed GregKH for comment hopefully.

On Saturday 18 March 2006 16:44, Nick Piggin wrote:
> Con Kolivas wrote:
> > I added the suspend_pass member to struct scan_control within an #ifdef
> > CONFIG_PM to allow it to not be unnecessarily compiled in in the
> > !CONFIG_PM case and wanted to avoid having the #ifdefs in vmscan.c so
> > moved it to a header file.
>
> Oh no, that rule thumb isn't actually "don't put ifdefs in .c files", but
> people commonly say it that way anyway. The rule is actually that you
> should put ifdefs in declarations rather than call/usage sites.

There isn't a formal reference to this in the Codingstyle documentation, but 
Greg's 2002 ols presentation says simply says no ifdefs in .c files.

http://www.kroah.com/linux/talks/ols_2002_kernel_codingstyle_talk/html/mgp00031.html

I'm confused now because I've been working very hard to do this with all code.

> You did the right thing there by introducing the accessor, which moves the
> ifdef out of code that wants to query the member right? But you can still
> leave it in the .c file if it is local (which it is).

Once again I'm happy to do the right thing; I'm just not sure what that is.

Cheers,
Con