From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: peterz@infradead.org, paulmck@linux.vnet.ibm.com,
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 20:48:45 +0100 [thread overview]
Message-ID: <52EBFE1D.4020201@linutronix.de> (raw)
In-Reply-To: <20140131143441.478f79ee@gandalf.local.home>
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
next prev parent reply other threads:[~2014-01-31 19:48 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
2014-01-31 19:34 ` Steven Rostedt
2014-01-31 19:48 ` Sebastian Andrzej Siewior [this message]
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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