From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH] netpoll: Fix carrier detection for drivers that are
 using phylib
Date: Thu, 09 Jul 2009 16:51:19 +0200
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Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Anton Vorontsov <avorontsov@ru.mvista.com>,
	Andrew Morton <akpm@linux-foundation.org>, oleg@redhat.com,
	mingo@elte.hu, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
To: Matt Mackall <mpm@selenic.com>
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On Thu, 2009-07-09 at 09:43 -0500, Matt Mackall wrote:

> Yeah, that's what I had in mind. Probably throw in a define:
> 
> /* for disabling scheduling in early boot */
> #define PREEMPT_EARLY (1 + PREEMPT_ACTIVE)
> 
> and slap a comment on the sub_preempt_count().

Right, and visit all the other arch init code ;-)

I'll wait to see if Ingo has anything to say about it and then complete
this thing.

> Does anything actually use scheduler_running yet? Perhaps my tree is
> old.

# git grep scheduler_running
kernel/sched.c:static __read_mostly int scheduler_running;
kernel/sched.c: scheduler_running = 1;
kernel/sched_rt.c:      if (unlikely(!scheduler_running))
kernel/sched_rt.c:      if (unlikely(!scheduler_running))

If memory serves there used to be more, but I think that migrated into
kernel/sched_clock.c, which has sched_clock_running.

> Also, might_sleep's use of system_state probably bears revisiting.

Yeah, all that code is from long before we had scheduler_running (which
was introduced around CFS/.23).