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Message-ID: <5595025C.5050306@linux.intel.com>
Date: Thu, 02 Jul 2015 17:20:28 +0800
From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
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To: "Xiao, Jin" <jin.xiao@intel.com>, Joerg Roedel <jroedel@suse.de>
CC: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org,
        bp@suse.de, boris.ostrovsky@oracle.com, dave.hansen@linux.intel.com,
        rientjes@google.com, imammedo@redhat.com, paulmck@linux.vnet.ibm.com,
        linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org,
        xinhuix.pan@intel.com
Subject: Re: [PATCH] smpboot.c: move setup_vector_irq after set_cpu_online
References: <1435811074-30062-1-git-send-email-jin.xiao@intel.com> <20150702065215.GD16233@suse.de> <5594E1F2.5060602@intel.com>
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On 2015/7/2 15:02, Xiao, Jin wrote:
> Hi Joerg,
>
> On 7/2/2015 2:52 PM, Joerg Roedel wrote:
>> Hi Jin,
>>
>> On Thu, Jul 02, 2015 at 12:24:34PM +0800, xiao jin wrote:
>>> [  106.107851] BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
>>> [  106.116702] IP:
>>> [  106.118490]  [<ffffffff810044f6>] check_irq_vectors_for_cpu_disable+0x76/0x180
>> This might be the same issue I fixed with:
>>
>>     d97eb8966c91 x86/irq: Check for valid irq descriptor in check_irq_vectors_for_cpu_disable()
>>
>> Can you try whether applying this patch on your kernel fixes your
>> issue?
>>
> Yes, I agree d97eb8966c91 fix the IPANIC. I just notice a description from http://lkml.kernel.org/r/20150204132754.GA10078@suse.de.
>
> I wish to share the debug result and root cause from my side.

commit d97eb8966c91f2c9d05f0a22eb89ed5b76d966d1 looks like a workaround.

Could Jin's patch be merged also?
free_msi_irqs does have a race with smp_callin=>..=>__setup_vector_irq.

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