From mboxrd@z Thu Jan  1 00:00:00 1970
From: Theodore Ts'o <tytso-3s7WtUTddSA@public.gmane.org>
Subject: Re: [PATCH 3/3] sched: Implement interface for cgroup unified
 hierarchy
Date: Sun, 25 Oct 2015 06:41:45 -0400
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To: Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Mike Galbraith <umgwanakikbuti-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Paul Turner <pjt-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>, Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, kernel-team <kernel-team-b10kYP2dOMg@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>

On Sun, Oct 25, 2015 at 10:33:32AM +0100, Ingo Molnar wrote:
> 
> Hm, that's weird - all our sched_*() system call APIs that set task scheduling 
> priorities are fundamentally per thread, not per process. Same goes for the old 
> sys_nice() interface. The scheduler has no real notion of 'process', and certainly 
> not at the system call level.
>

I suspect the main issue is that the games programmers were trying to
access it via libc / pthreads, which hides a lot of the power
available at the raw syscall level.  This is probably more of a
"tutorial needed for userspace programmers" issue, at a guess.

	  	     	       		    	   - Ted