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Message-ID: <1371261741.21896.20.camel@pasglop>
Subject: Re: Regression in RCU subsystem in latest mainline kernel
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Steven Rostedt <rostedt@goodmis.org>
Date: Sat, 15 Jun 2013 12:02:21 +1000
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Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, paulmck@linux.vnet.ibm.com,
 Rojhalat Ibrahim <imr@rtschenk.de>, linux-kernel@vger.kernel.org
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On Fri, 2013-06-14 at 17:06 -0400, Steven Rostedt wrote:
> I was pretty much able to reproduce this on my PA Semi PPC box. Funny
> thing is, when I type on the console, it makes progress. Anyway, it
> seems that powerpc has an issue with irq_work(). I'll try to get some
> time either tonight or next week to figure it out.

Does this help ?

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 5cbcf4d..ea185e0 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -162,7 +162,7 @@ notrace unsigned int __check_irq_replay(void)
 	 * in case we also had a rollover while hard disabled
 	 */
 	local_paca->irq_happened &= ~PACA_IRQ_DEC;
-	if (decrementer_check_overflow())
+	if ((happened & PACA_IRQ_DEC) || decrementer_check_overflow())
 		return 0x900;
 
 	/* Finally check if an external interrupt happened */

Cheers,
Ben.