Re: [PATCH 1/2] mm/zsmalloc: adjust order of functions

From: Minchan Kim
Date: Tue Dec 16 2014 - 00:44:12 EST


On Tue, Dec 16, 2014 at 12:08:02PM +0800, Ganesh Mahendran wrote:
> Hello Minchan,
>
>
> 2014-12-16 8:40 GMT+08:00 Minchan Kim <minchan@xxxxxxxxxx>:
> > Hello Ganesh,
> >
> > On Sat, Dec 13, 2014 at 09:43:23PM +0800, Ganesh Mahendran wrote:
> >> Currently functions in zsmalloc.c does not arranged in a readable
> >> and reasonable sequence. With the more and more functions added,
> >> we may meet below inconvenience. For example:
> >>
> >> Current functions:
> >> void zs_init()
> >> {
> >> }
> >>
> >> static void get_maxobj_per_zspage()
> >> {
> >> }
> >>
> >> Then I want to add a func_1() which is called from zs_init(), and this new added
> >> function func_1() will used get_maxobj_per_zspage() which is defined below zs_init().
> >>
> >> void func_1()
> >> {
> >> get_maxobj_per_zspage()
> >> }
> >>
> >> void zs_init()
> >> {
> >> func_1()
> >> }
> >>
> >> static void get_maxobj_per_zspage()
> >> {
> >> }
> >>
> >> This will cause compiling issue. So we must add a declaration:
> >> static void get_maxobj_per_zspage();
> >> before func_1() if we do not put get_maxobj_per_zspage() before func_1().
> >
> > Yes, I suffered from that when I made compaction but was not sure
> > it's it was obviously wrong.
> > Stupid question:
> > What's the problem if we should put function declaration on top of
> > source code?
>
> There is no problem if we do this. But if we obey to some coding
> style, then it will
> be convenient for the later developers.
> Normally I put the global or important interface function at the
> bottom of the file, and
> the static or helper functions on the top. Because usually global
> functions is the caller, and
> static functions is the callee.
>
> >
> >>
> >> In addition, puting module_[init|exit] functions at the bottom of the file
> >> conforms to our habit.
> >
> > Normally, we do but without any strong reason, I don't want to rub git-blame
> > by clean up patches.
>
> Sorry, I did not consider this when I made this patch.:)
>
> >
> > In summary, I like this patch but don't like to churn git-blame by clean-up
> > patchset without strong reason so I need something I am sure.
>
> Now, zsmalloc module is active in development. More and more changes
> will be included.
> If we do not clean up, then this file may looks messy.
>
> Thanks a lot.

Okay, you move my heart

Acked-by: Minchan Kim <minchan@xxxxxxxxxx>

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