Re: [Xen-devel] [PATCH 2 of 5] early PV on HVM

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 03/12/2010 11:09 AM, Stefano Stabellini wrote:
> My version is not 64-bit specific, should I move it to a new file
> anyway?
>
> I was trying to keep the differences with Sheng's version low, but in
> this case I am not quite sure how to manage it.
> Suggestions are welcome.
>    

My rough rules for code layout (in no particular order):

    * keep similar functions together (even if they're not necessarily
      sharing common code)
    * dislike externs and cross-file references (ie, prefer static
      functions/data) -> keep code sharing functions/data together
    * dislike #ifdef CONFIG_x within files; prefer Makefile rules to
      either completely compile or not compile files
    * dislike dumping-ground files
    * dislike too-small files
    * dislike moving code between files, so its better to get it right
      from the start (it makes merging harder)

So in this case, enlighten.c is the general setup/init/misc file in 
xen/.  I've been trying to move things out of it to reduce its dumping 
ground-ness.  In your case, the changes are clearly init, so they 
probably belong there.  They're compiled unconditionally, so there's no 
#ifdef.  They're fairly small so they would probably be too small in a 
separate file (unless its likely to get bigger?).  So keep in enlighten.c.

(In Sheng's version of this patch, it has more code and is conditionally 
compiled, so I think the balance tips the other way.)

     J