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Date:	Fri, 31 Jan 2014 20:48:45 +0100
From:	Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:	Steven Rostedt <rostedt@...dmis.org>
CC:	peterz@...radead.org, paulmck@...ux.vnet.ibm.com,
	linux-rt-users@...r.kernel.org, linux-kernel@...r.kernel.org,
	tglx@...utronix.de, Clark Williams <williams@...hat.com>
Subject: Re: [PATCH 2/2] timer: really raise softirq if there is irq_work
 to do

On 01/31/2014 08:34 PM, Steven Rostedt wrote:
> There's flags that determine when the next call should be invoked. The
> irq_work_run() should return immediately if it was already done by the
> arch specific call. The work wont be called twice.

Well, it is called twice. It just does nothing because the list is
empty & returns.

> As I have worked on code that uses irq_work() I can say that we want
> the arch specific interrupts. For those architectures that don't have
> it will experience larger latencies for the work required. It's
> basically, a "too bad" for them.

How "bad" is it? Is this something generic or just not getting
perf events fast enough out? Most users don't seem to require small
latencies.

> But to answer your question, no we want the immediate response.
> 
> -- Steve

Sebastian
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