From mboxrd@z Thu Jan  1 00:00:00 1970
From: ngwilliams@gmail.com (Nathan Williams)
Date: Tue, 21 Jun 2016 12:31:54 +1000
Subject: What is the point of this function?
In-Reply-To: <CAPQXMLFvDqbRKfpyqy+yfG8HUyFra3JuX3bmMqhgtV-OTw_Umg@mail.gmail.com>
References: <CAPQXMLHzXhKzZyZx_0YWZMkr6MdPNDdd38Fh=vabGcRMcKXXjw@mail.gmail.com>
	<CAPQXMLFvDqbRKfpyqy+yfG8HUyFra3JuX3bmMqhgtV-OTw_Umg@mail.gmail.com>
Message-ID: <1466476314.28067.8.camel@linux>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

On Tue, 2016-06-21 at 00:48 +0200, Andrea Benelli wrote:
> Hello, i was looking at the linux/sched.h (kernel version 4.6.2)
> source code and i found this function at line 1174: 
> 
> static inline bool cpus_share_cache(int this_cpu, int that_cpu)
> {
>         return true;
> }
> 
> I'm not able to understand the utility of a function that just return
> a true value. 
> i've noticed that there are a lot of functions like this (function
> that just return a constant). 

Hi Andrea,

That's the case for when CONFIG_SMP isn't defined. What happens when
CONFIG_SMP is defined?

I suggest having a look through the code with a Linux cross reference:

http://lxr.free-electrons.com/ident?v=4.6;i=cpus_share_cache

Regards,
Nathan