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From: Thomas Gleixner <tglx@linutronix.de>
To: "Woodruff, Richard" <r-woodruff2@ti.com>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>
Subject: Re: bug seen with dynticks from CONFIG_HARDIRQS_SW_RESEND
Date: Thu, 17 May 2007 12:10:59 +0200	[thread overview]
Message-ID: <1179396659.3764.40.camel@chaos> (raw)
In-Reply-To: <3B6D69C3A9EBCA4BA5DA60D913027429010253CD@dlee13.ent.ti.com>

On Wed, 2007-05-16 at 18:20 -0500, Woodruff, Richard wrote:
> The crashes were because the frame pointer per_cpu____irq_regs value was
> 0.  That code does a user_mode(get_irq_regs()).  Currently regs is set
> only upon real hardware entry on an irq.
> 
> The crash path shows resend_irqs() could be called with in a context
> where set_irq_regs() was not executed.  In one specific case this was
> from
> softirq->tasklet_action(resend_tasklet)->resend_irqs->handle_level_irq->
> handle_IRQ_event->...->profile_tick.
> 
> It seems anyone calling kernel/irq/manage.c:enable_irq() at the wrong
> time can trigger this crash.

which code is disabling / enabling the timer interrupt ?

	tglx



  reply	other threads:[~2007-05-17 10:06 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-16 23:20 bug seen with dynticks from CONFIG_HARDIRQS_SW_RESEND Woodruff, Richard
2007-05-17 10:10 ` Thomas Gleixner [this message]
2007-05-17 20:14   ` Woodruff, Richard
2007-05-17 20:38     ` Thomas Gleixner
2007-05-17 22:24       ` Woodruff, Richard
2007-05-18  7:49         ` Thomas Gleixner
2008-04-18 15:43           ` Higer latency with dynamic tick (need for an io-ondemand govenor?) Woodruff, Richard
2008-04-19  3:45             ` [linux-pm] " David Brownell
2008-04-19  7:13               ` Thomas Gleixner
2008-04-19 22:49                 ` david
2008-04-20  3:51                   ` David Brownell
2008-04-20  6:19             ` Arjan van de Ven
2008-04-20 14:09               ` Woodruff, Richard
2008-04-20 12:41             ` Andi Kleen
2008-04-20 14:21               ` Woodruff, Richard
2008-04-20 14:26                 ` Andi Kleen

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