From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp04.au.ibm.com (e23smtp04.au.ibm.com [202.81.31.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp04.au.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 0F873B8133 for ; Mon, 1 Mar 2010 23:58:20 +1100 (EST) Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [202.81.31.246]) by e23smtp04.au.ibm.com (8.14.3/8.13.1) with ESMTP id o21Csek8021248 for ; Mon, 1 Mar 2010 23:54:40 +1100 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o21CqmEN1646618 for ; Mon, 1 Mar 2010 23:52:48 +1100 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o21CwJSv024171 for ; Mon, 1 Mar 2010 23:58:19 +1100 Subject: [PATCH v2 2/3] powerpc: move checks in pseries_mach_cpu_die() To: Benjamin Herrenschmidt , Anton Blanchard From: Vaidyanathan Srinivasan Date: Mon, 01 Mar 2010 18:28:16 +0530 Message-ID: <20100301125816.26066.34262.stgit@drishya.in.ibm.com> In-Reply-To: <20100301123519.26066.8639.stgit@drishya.in.ibm.com> References: <20100301123519.26066.8639.stgit@drishya.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linuxppc-dev@ozlabs.org, Gautham R Shenoy List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Rearrange condition checks for better code readability and prevention of possible race conditions when preferred_offline_state can potentially change during the execution of pseries_mach_cpu_die(). The patch will make pseries_mach_cpu_die() put cpu in one of the consistent states and not hit the run over BUG() Signed-off-by: Vaidyanathan Srinivasan Cc: Gautham R Shenoy --- arch/powerpc/platforms/pseries/hotplug-cpu.c | 30 +++++++++++++------------- 1 files changed, 15 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 9be7af4..39ecb40 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -140,25 +140,25 @@ static void pseries_mach_cpu_die(void) if (!get_lppaca()->shared_proc) get_lppaca()->donate_dedicated_cpu = 0; get_lppaca()->idle = 0; - } - if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) { - unregister_slb_shadow(hwcpu, __pa(get_slb_shadow())); + if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) { + unregister_slb_shadow(hwcpu, __pa(get_slb_shadow())); - /* - * Call to start_secondary_resume() will not return. - * Kernel stack will be reset and start_secondary() - * will be called to continue the online operation. - */ - start_secondary_resume(); + /* + * Call to start_secondary_resume() will not return. + * Kernel stack will be reset and start_secondary() + * will be called to continue the online operation. + */ + start_secondary_resume(); + } + } - } else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) { + /* Requested state is CPU_STATE_OFFLINE at this point */ + WARN_ON(get_preferred_offline_state(cpu) != CPU_STATE_OFFLINE); - set_cpu_current_state(cpu, CPU_STATE_OFFLINE); - unregister_slb_shadow(hard_smp_processor_id(), - __pa(get_slb_shadow())); - rtas_stop_self(); - } + set_cpu_current_state(cpu, CPU_STATE_OFFLINE); + unregister_slb_shadow(hwcpu, __pa(get_slb_shadow())); + rtas_stop_self(); /* Should never get here... */ BUG();