From: Nick Piggin <npiggin@suse.de>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org, vegard.nossum@gmail.com,
stable@kernel.org, akpm@linux-foundation.org,
penberg@cs.helsinki.fi
Subject: Re: [PATCH] v4 Teach RCU that idle task is not quiscent state at boot
Date: Wed, 25 Feb 2009 18:18:42 +0100 [thread overview]
Message-ID: <20090225171842.GN22785@wotan.suse.de> (raw)
In-Reply-To: <20090225171249.GD6797@linux.vnet.ibm.com>
On Wed, Feb 25, 2009 at 09:12:49AM -0800, Paul E. McKenney wrote:
> On Wed, Feb 25, 2009 at 05:26:45PM +0100, Nick Piggin wrote:
> > I wonder if you couldn't leave cpu_rq(cpu)->idle as NULL until right
> > up to the point where it actually becomes the "idle" thread? This
> > would make idle_cpu() more truthful for all other callers in early
> > boot code too. And rcupdate shouldn't need any changes (except the
> > num_online_cpus() == 1 shortcut probably remains as a nice opt).
>
> It looked to me that the idle task initialization was moved early
> to allow interrupt handlers to see a more normal environment, but I
> could easily be confused here.
I think we might be OK. I think interrupt handlers shouldn't care
so much about whether the cpu is idle or not (and seeing !idle
here would be more accurate anyway).
next prev parent reply other threads:[~2009-02-25 17:19 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-23 16:16 [PATCH] " Paul E. McKenney
2009-02-23 17:13 ` Ingo Molnar
2009-02-23 20:43 ` [PATCH] v2 " Paul E. McKenney
2009-02-24 4:02 ` Nick Piggin
2009-02-24 5:08 ` Paul E. McKenney
2009-02-24 14:50 ` Paul E. McKenney
2009-02-25 0:29 ` [PATCH] v3 " Paul E. McKenney
2009-02-25 4:12 ` Nick Piggin
2009-02-25 4:43 ` Paul E. McKenney
2009-02-25 14:19 ` [PATCH] v4 " Paul E. McKenney
2009-02-25 16:00 ` Ingo Molnar
2009-02-25 16:26 ` Nick Piggin
2009-02-25 17:12 ` Paul E. McKenney
2009-02-25 17:18 ` Nick Piggin [this message]
2009-02-25 17:36 ` Paul E. McKenney
2009-02-25 17:08 ` Paul E. McKenney
2009-02-26 3:09 ` Ingo Molnar
2009-02-25 18:38 ` Vegard Nossum
2009-02-25 19:01 ` Paul E. McKenney
2009-02-26 2:03 ` [PATCH] v5 " Paul E. McKenney
2009-02-26 3:08 ` Ingo Molnar
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