Message-ID: <1329387265.2293.195.camel@twins>
Subject: Re: [PATCH RFC 0/4] Scheduler idle notifiers and users
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>,
        Saravana Kannan <skannan@codeaurora.org>, Ingo Molnar <mingo@elte.hu>,
        linaro-kernel@lists.linaro.org, Nicolas Pitre <nico@fluxnic.net>,
        Oleg Nesterov <oleg@redhat.com>, cpufreq@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Anton Vorontsov <anton.vorontsov@linaro.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Mike Chan <mike@android.com>, Dave Jones <davej@redhat.com>,
        Todd Poynor <toddpoynor@google.com>, kernel-team@android.com,
        linux-arm-kernel@lists.infradead.org,
        Arjan Van De Ven <arjan@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 16 Feb 2012 11:14:25 +0100
In-Reply-To: <1329363097.3772.46.camel@pasglop>
References: <20120208013959.GA24535@panacea>
	 <1328670355.2482.68.camel@laptop> <20120208202314.GA28290@redhat.com>
	 <1328736834.2903.33.camel@pasglop> <20120209075106.GB18387@elte.hu>
	 <4F35DD3E.4020406@codeaurora.org> <20120211144530.GA497@elte.hu>
	 <4F3AEC4E.9000303@codeaurora.org> <1329313085.2293.106.camel@twins>
	 <20120215140245.GB27825@n2100.arm.linux.org.uk>
	 <1329318063.2293.136.camel@twins> <1329363097.3772.46.camel@pasglop>
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7BIT
Mime-Version: 1.0
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 777
Lines: 16

On Thu, 2012-02-16 at 14:31 +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2012-02-15 at 16:01 +0100, Peter Zijlstra wrote:
> > 
> > Thing is, the scheduler doesn't care about completion, all it needs is
> > to be able to kick-start the thing atomically. So you really have to
> > wait for it or can you do an interrupt driven state machine?
> 
> Or the scheduler callback could schedule a wq to do the job ?

That'll end up being very ugly due to lock inversion etc. If we can get
out of this using self-IPIs I'd much prefer that.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/