From: David Brownell <david-b@pacbell.net>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
me@felipebalbi.com, linux-kernel@vger.kernel.org,
linux-input@vger.kernel.org, felipe.balbi@nokia.com,
dmitry.torokhov@gmail.com, sameo@openedhand.com
Subject: Re: lockdep and threaded IRQs (was: ...)
Date: Mon, 2 Mar 2009 14:09:20 -0800 [thread overview]
Message-ID: <200903021409.21344.david-b@pacbell.net> (raw)
In-Reply-To: <1236030106.5330.1553.camel@laptop>
On Monday 02 March 2009, Peter Zijlstra wrote:
> > > How so?, its the natural extension of that work.
> >
> > Not the work to shrink the amount of time IRQ latencies
> > by shrinking the amount of time IRQs are disabled by
> > IRQ handlers.
>
> Ugh, that's done by pushing work out of the hardirq context,
That's one of many techniques currently used.
Tradeoffs don't always favor larger driver updates
and re-validation though. Sometimes it's simpler
to just leverage the reality that "hardirq context"
does not require using IRQF_DISABLED.
> not by doing silly things like enabling irqs from hardirq context.
Somehow I'm certain you have NOT analysed every one of the
thousands of IRQ handlers in various Linux drivers to know
with certainty that's not the reason IRQ_DISABLED is cleared.
There are also *other* reasons to leave IRQ_DISABLED clear.
- Dave
next prev parent reply other threads:[~2009-03-02 22:09 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-27 19:28 [PATCH 1/2] input: misc: add twl4030-pwrbutton driver Felipe Balbi
2009-02-27 19:28 ` [PATCH 2/2] mfd: twl4030: add twl4030-pwrbutton as our child Felipe Balbi
2009-02-27 20:36 ` Andrew Morton
2009-02-27 21:58 ` David Brownell
2009-02-27 22:09 ` Felipe Balbi
2009-02-27 22:12 ` Andrew Morton
2009-02-27 23:20 ` David Brownell
2009-02-27 23:42 ` Andrew Morton
2009-07-22 19:27 ` Trilok Soni
2009-07-22 22:25 ` David Brownell
2009-02-27 20:33 ` [PATCH 1/2] input: misc: add twl4030-pwrbutton driver Andrew Morton
2009-02-27 20:37 ` Felipe Balbi
2009-02-27 21:50 ` lockdep and threaded IRQs (was: [PATCH 1/2] input: misc: add twl4030-pwrbutton driver) David Brownell
2009-02-27 22:09 ` Andrew Morton
2009-02-27 23:18 ` lockdep and threaded IRQs (was: ...) David Brownell
2009-02-27 23:32 ` Andrew Morton
2009-02-28 0:01 ` Andrew Morton
2009-02-28 2:30 ` David Brownell
2009-02-28 2:39 ` Andrew Morton
2009-02-28 4:46 ` David Brownell
2009-02-28 5:12 ` Andrew Morton
2009-02-28 6:17 ` David Brownell
2009-02-28 11:13 ` Thomas Gleixner
2009-02-28 12:16 ` David Brownell
2009-02-28 16:42 ` Thomas Gleixner
2009-02-28 20:02 ` David Brownell
2009-02-28 20:55 ` Thomas Gleixner
2009-02-28 21:13 ` Thomas Gleixner
2009-02-28 22:37 ` David Brownell
2009-02-28 22:05 ` David Brownell
2009-03-01 9:43 ` Thomas Gleixner
2009-03-01 22:54 ` David Brownell
2009-03-02 13:16 ` Peter Zijlstra
2009-03-02 21:04 ` David Brownell
2009-03-02 21:16 ` Peter Zijlstra
2009-03-02 21:29 ` Andrew Morton
2009-03-02 21:37 ` David Brownell
2009-03-02 21:41 ` Peter Zijlstra
2009-03-02 22:09 ` David Brownell [this message]
2009-03-02 22:19 ` Peter Zijlstra
2009-03-02 22:40 ` David Brownell
2009-03-02 22:51 ` Peter Zijlstra
2009-03-02 23:29 ` David Brownell
2009-03-03 7:45 ` Peter Zijlstra
2009-03-02 22:46 ` lockdep and threaded IRQs David Miller
2009-03-02 22:57 ` Andrew Morton
2009-03-02 23:07 ` Peter Zijlstra
2009-03-02 23:02 ` Peter Zijlstra
2009-03-02 23:35 ` lockdep and threaded IRQs (was: ...) Alan Cox
2009-03-01 22:11 ` David Brownell
2009-02-28 11:48 ` lockdep and threaded IRQs Stefan Richter
2009-02-28 20:19 ` David Brownell
2009-02-28 21:10 ` Stefan Richter
2009-03-02 13:16 ` lockdep and threaded IRQs (was: ...) Peter Zijlstra
2009-03-02 22:10 ` David Brownell
2009-03-02 22:25 ` Peter Zijlstra
2009-03-02 23:20 ` David Brownell
2009-03-02 23:26 ` Ingo Molnar
2009-03-02 23:42 ` David Brownell
2009-03-02 23:53 ` Ingo Molnar
2009-03-03 0:33 ` David Brownell
2009-03-03 0:44 ` Ingo Molnar
2009-03-03 2:37 ` David Brownell
2009-03-03 9:27 ` Peter Zijlstra
2009-03-03 9:45 ` Ingo Molnar
2009-03-03 9:47 ` Alan Cox
2009-03-03 10:03 ` Ingo Molnar
2009-03-03 10:30 ` Alan Cox
2009-03-03 10:39 ` Peter Zijlstra
2009-03-03 10:48 ` Ingo Molnar
2009-03-03 11:13 ` Alan Cox
2009-03-03 11:33 ` Ingo Molnar
2009-03-03 11:19 ` Ingo Molnar
2009-03-18 1:04 ` David Brownell
2009-03-18 2:00 ` David Brownell
2009-03-18 2:14 ` [patch/rfc 0/2] handle_threaded_irq() David Brownell
2009-03-18 2:19 ` [patch/rfc 1/2] GENIRQ: add handle_threaded_irq() flow handler David Brownell
2009-03-18 12:00 ` Felipe Balbi
2009-03-18 18:31 ` David Brownell
2009-03-18 18:32 ` Felipe Balbi
2009-03-18 2:22 ` [patch/rfc 2/2] twl4030: use new " David Brownell
2009-03-03 11:53 ` lockdep and threaded IRQs (was: ...) Thomas Gleixner
2009-03-05 2:49 ` David Brownell
2009-03-06 14:40 ` Thomas Gleixner
2009-03-18 3:06 ` David Brownell
2009-03-02 23:48 ` David Brownell
2009-03-02 23:58 ` Ingo Molnar
2009-03-02 15:13 ` [PATCH] genirq: assert that irq handlers are indeed run in hardirq context Peter Zijlstra
2009-03-02 19:48 ` David Brownell
2009-03-02 22:01 ` [tip:irq/genirq] genirq: assert that irq handlers are indeed running " Peter Zijlstra
2009-03-02 23:15 ` Peter Zijlstra
2009-04-10 7:11 ` Eric Miao
2009-04-10 9:57 ` Thomas Gleixner
2009-02-28 11:20 ` lockdep and threaded IRQs Stefan Richter
2009-02-28 20:10 ` David Brownell
2009-02-28 5:51 ` [PATCH 1/2] input: misc: add twl4030-pwrbutton driver Trilok Soni
2009-02-28 12:05 ` [PATCH] mfd: twl4030: add twl4030-pwrbutton as our child Felipe Balbi
2009-02-28 22:23 ` [PATCH 1/2] input: misc: add twl4030-pwrbutton driver Dmitry Torokhov
2009-03-01 0:30 ` Felipe Balbi
2009-03-01 0:58 ` Dmitry Torokhov
2009-03-01 14:40 ` Felipe Balbi
2009-03-04 9:00 ` Dmitry Torokhov
2009-03-04 10:12 ` Felipe Balbi
2009-03-05 1:38 ` David Brownell
2009-03-05 23:54 ` David Brownell
2009-03-06 9:43 ` Dmitry Torokhov
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