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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>,
	peterz@infradead.org, paulmck@linux.vnet.ibm.com
Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	tglx@linutronix.de, Clark Williams <williams@redhat.com>
Subject: Re: [PATCH 2/2] timer: really raise softirq if there is irq_work to do
Date: Fri, 31 Jan 2014 20:26:54 +0100	[thread overview]
Message-ID: <52EBF8FE.3080608@linutronix.de> (raw)
In-Reply-To: <20140131125719.73340f6e@gandalf.local.home>

On 01/31/2014 06:57 PM, Steven Rostedt wrote:

> In vanilla Linux, irq_work_run() is called from update_process_times()
> when it is called from the timer interrupt. In -rt, there's reasons we

and in vanilla Linux some architectures (like x86 or sparc to name just
a few) overwrite arch_irq_work_raise() which means they provide
their "own" interrupt like callback. That means on those architectures
irq_work_run() gets invoked twice: once via update_process_times() and
via and once the custom interface.
So my question to the original inventor of this code: Peter, do we
really need that arch specific callback? Wouldn't one be enough? Is it
that critical that it can't wait to the next timer tick?

Sebastian


  parent reply	other threads:[~2014-01-31 19:27 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-31 14:34 [PATCH 1/2] irq_work: allow certain work in hard irq context Sebastian Andrzej Siewior
2014-01-31 14:34 ` [PATCH 2/2] timer: really raise softirq if there is irq_work to do Sebastian Andrzej Siewior
2014-01-31 17:07   ` Steven Rostedt
2014-01-31 17:11     ` Steven Rostedt
2014-01-31 17:42     ` Paul E. McKenney
2014-01-31 17:57       ` Steven Rostedt
2014-01-31 19:03         ` Paul E. McKenney
2014-01-31 19:26         ` Sebastian Andrzej Siewior [this message]
2014-01-31 19:34           ` Steven Rostedt
2014-01-31 19:48             ` Sebastian Andrzej Siewior
2014-01-31 19:56               ` Steven Rostedt
2014-01-31 20:05               ` Peter Zijlstra
2014-01-31 20:23                 ` Sebastian Andrzej Siewior
2014-01-31 20:29                   ` Peter Zijlstra
2014-01-31 19:54             ` Peter Zijlstra
2014-01-31 19:06     ` Sebastian Andrzej Siewior
2014-02-02  4:22 ` [PATCH 1/2] irq_work: allow certain work in hard irq context Mike Galbraith
2014-02-02 20:10   ` Sebastian Andrzej Siewior
2014-02-03  2:43     ` Mike Galbraith
2014-02-03  4:00     ` Mike Galbraith
2014-02-03  8:31       ` Sebastian Andrzej Siewior
2014-02-03  9:26         ` Mike Galbraith

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