From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id DDDECB6FA8 for ; Thu, 3 May 2012 14:26:26 +1000 (EST) Message-ID: <1336019173.2653.12.camel@pasglop> Subject: Re: [PATCH] powerpc: use local var instead of local_paca->irq_happened directly in __check_irq_replay From: Benjamin Herrenschmidt To: Wang Sheng-Hui Date: Thu, 03 May 2012 14:26:13 +1000 In-Reply-To: <4FA1EE2C.6050201@gmail.com> References: <4FA1E527.1090807@gmail.com> <1336011306.2653.3.camel@pasglop> <4FA1EE2C.6050201@gmail.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: Stephen Rothwell , linux-kernel@vger.kernel.org, Milton Miller , Anton Blanchard , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2012-05-03 at 10:32 +0800, Wang Sheng-Hui wrote: > > It should not as __check_irq_replay() should always be called > > with interrupts hard disabled... Do you see any code path > > where that is not the case ? > > Since __check_irq_replay() should always be called with interrupts > hard disabled, I think it's harmless to use local var here. No, that would be papering over the real problem. All oprofile does is trigger perfmon interrupts (which act as some kind of NMI when soft-disabled but should be masked by MSR:EE when hard disabled). So there's a deeper issue here that we need to understand before we can propose a fix. IE. It should not have happened. Cheers, Ben.