Re: [PATCH V2 5/8] x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files

[Mike Travis]

On 9/10/2019 11:04 PM, Ingo Molnar wrote:
> * Mike Travis <mike.travis@xxxxxxx> wrote:
>
> > @@ -1596,7 +1687,7 @@ static void __init uv_system_init_hub(vo
> >   	uv_nmi_setup();
> >   	uv_cpu_init();
> >   	uv_scir_register_cpu_notifier();
> > -	proc_mkdir("sgi_uv", NULL);
> > +	uv_setup_proc_files(0);
>
> This slipped through previously: platform drivers have absolutely no
> business mucking in /proc.
>
> Please describe the hardware via sysfs as pretty much everyone else does.
>
> Thanks,
>
> 	Ingo

If I was doing it now I definitely would put it in the sysfs realm.  The 
problem is Jack did it back in (I think) 2007.  The earliest commit I 
could find:

commit a3d732f93785da17e0137210deadb4616f5536fc
Author: Cliff Wickman <cpw@xxxxxxx>
Date:   Mon Nov 10 16:16:31 2008 -0600

    x86, UV: fix redundant creation of sgi_uv

    Impact: fix double entry creation in /proc

And in the past 12 years probably a hundred user programs are now keying 
of the presence of /proc/sgi_uv to signal this is indeed a UV system. 
Changing the location of this node also affects all the UV utilities 
including those not written by us.