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From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Nicolas Pitre <nico@fluxnic.net>,
	Linus Torvalds <torvalds@osdl.org>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-arch@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Andi Kleen <andi@firstfloor.org>,
	David Miller <davem@davemloft.net>,
	Greg Kroah-Hartman <gregkh@suse.de>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Russell King <rmk@arm.linux.org.uk>
Subject: Re: [patch 0/2] Run interrupt handlers always with interrupts disabled
Date: Fri, 26 Mar 2010 10:28:12 +0100	[thread overview]
Message-ID: <1269595692.12097.128.camel@laptop> (raw)
In-Reply-To: <20100326092023.GH27394@elte.hu>

On Fri, 2010-03-26 at 10:20 +0100, Ingo Molnar wrote:
> * Russell King <rmk@arm.linux.org.uk> wrote:
> 
> > On Fri, Mar 26, 2010 at 12:06:44AM -0000, Thomas Gleixner wrote:
> > > The following patch series removes the IRQF_DISABLED functionality
> > > from the core interrupt code and runs all interrupt handlers with
> > > interrupts disabled.
> > 
> > As was covered in previous discussions, what about drivers such as SMC91x 
> > which take a long time to retrieve packets from the hardware? Always running 
> > handlers with IRQs disabled will kill things such as serial on these 
> > platforms.
> 
> As long as it's rare (which it is) i dont see a problem: you can enable 
> interrupts in the handler by using local_irq_enable(), like the IDE PIO 
> drivers do. That way it's documented a bit better as well, because it shows 
> the precise source of the latency, with a big comment explaining it, etc.

Or alternatively, use threaded interrupts for such slow hardware.

  parent reply	other threads:[~2010-03-26  9:28 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-26  0:06 [patch 0/2] Run interrupt handlers always with interrupts disabled Thomas Gleixner
2010-03-26  0:06 ` [patch 1/2] genirq: Run irq handlers " Thomas Gleixner
2010-03-26  6:13   ` Andi Kleen
2010-03-26 13:05     ` Thomas Gleixner
2010-03-30  5:33       ` Andi Kleen
2010-03-31 11:16         ` Thomas Gleixner
2010-04-02  9:31           ` Pavel Machek
2010-04-02 20:42             ` Thomas Gleixner
2010-04-02 21:09               ` Pavel Machek
2010-04-02 21:31                 ` Peter Zijlstra
2010-04-02 22:51                 ` Thomas Gleixner
2010-04-03  4:45                   ` Pavel Machek
2010-04-03  4:45                     ` Pavel Machek
2010-05-25 20:32   ` Venkatesh Pallipadi
2010-03-26  0:06 ` [patch 2/2] genirq: Remove IRQF_DISABLED from core code Thomas Gleixner
2010-03-26  0:06   ` Thomas Gleixner
2010-03-26  6:20   ` Andi Kleen
2010-03-26 11:19     ` Thomas Gleixner
2010-03-26 11:19       ` Thomas Gleixner
2010-03-26  3:34 ` [patch 0/2] Run interrupt handlers always with interrupts disabled David Miller
2010-03-26  8:14 ` Russell King
2010-03-26  8:14   ` Russell King
2010-03-26  9:20   ` Ingo Molnar
2010-03-26  9:20     ` Ingo Molnar
2010-03-26  9:28     ` Peter Zijlstra [this message]
2010-03-26 12:02       ` Jamie Lokier
2010-03-26  9:59     ` Alan Cox
2010-03-26 10:08       ` Peter Zijlstra
2010-03-26 10:12         ` Andi Kleen
2010-03-26 10:53         ` Ingo Molnar
2010-03-26 12:00         ` Nicolas Pitre
2010-03-26 12:06           ` Jamie Lokier

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