[Devel] Re: [RFC][PATCH] rename 'struct pid'

[Kirill Korotaev]

Pavel Emelianov wrote:
> Dave Hansen wrote:
> 
>>On Tue, 2007-04-10 at 22:52 -0600, Eric W. Biederman wrote:
>>
>>>Dave Hansen <hansendc at us.ibm.com> writes:
>>>
>>>>>A pid (pid_t or
>>>>>struct pid) isn't just an identfier it is a handle to processes.
>>>>>struct pid just does so more directly because it is inside the kernel.
>>>>
>>>>Let's face it, "pid" has a meaning.  It's a number.  It's what you
>>>>kill(1).  The meaning has been there for a long, long time.  'struct
>>>>pid' is a completely different concept, and it's certainly more than
>>>>"just a number".
>>>
>>>Yes.  "pid" has a meaning.  The meaning is old and well established.
>>>That meaning is not just a number, just like a file descriptor is not
>>>just a number.
>>
>>That's a great example.  Userspace fds are to 'struct file' as pids are
>>to 'struct pid', right?
>>
>>I actually think 'struct file' is a pretty good name.  Think of what
>>do_sys_open() might look like if we called 'struct file' 'struct fd'
>>instead and 'fdp' instead of 'filp'.
>>
>>We end up with lines like:
>>
>>	fd_install(fd, fdp);
>>
>>Which makes it confusing which fd we're dealing with or what the 'fd_'
>>in the name refers to, the 'fd' or the 'fdp'.  It makes quite a bit of
>>sense to have 'fd' and 'struct file' named quite distinctly.
> 
> 
> Agree. int fd is a *file* descriptor, i.e. a number that describes
> a file, which is a struct file essentially. That's the way pids must
> be represented. E.g. the pid_t is a number, that references some
> kernel-space object. This object is to be called somehow more
> descriptive than just struct pid.
> 
> Maybe it's worth renaming struct pid into struct pid_struct to
> represent the fact, that this is a pid, but also a structure?
it helps struct name only.
while fields should be renamed as well somehow.

Kirill