From: Wanpeng Li <wanpeng.li@linux.intel.com>
To: Ingo Molnar <mingo@redhat.com>
Cc: hpa@zytor.com, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
x86@kernel.org, Borislav Petkov <bp@alien8.de>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
David Rientjes <rientjes@google.com>,
Prarit Bhargava <prarit@redhat.com>,
Steven Rostedt <srostedt@redhat.com>,
Jan Kiszka <jan.kiszka@siemens.com>,
Toshi Kani <toshi.kani@hp.com>,
linux-kernel@vger.kernel.org, Zhang Yang <yang.z.zhang@intel.com>,
Wanpeng Li <wanpeng.li@linux.intel.com>
Subject: Re: [PATCH v4] x86, hotplug: fix llc shared map unreleased during cpu hotplug
Date: Thu, 4 Sep 2014 17:34:14 +0800 [thread overview]
Message-ID: <20140904093414.GA7296@kernel> (raw)
In-Reply-To: <20140904085641.GA6311@kernel>
Hi Ingo,
On Thu, Sep 04, 2014 at 04:56:41PM +0800, Wanpeng Li wrote:
>On Thu, Sep 04, 2014 at 07:20:34AM +0200, Ingo Molnar wrote:
>>
>>* Wanpeng Li <wanpeng.li@linux.intel.com> wrote:
>>
>>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
>>> IP: [..] find_busiest_group
>>> PGD 5a9d5067 PUD 13067 PMD 0
>>> Oops: 0000 [#3] SMP
>>> [...]
>>> Call Trace:
>>> load_balance
>>> ? _raw_spin_unlock_irqrestore
>>> idle_balance
>>> __schedule
>>> schedule
>>> schedule_timeout
>>> ? lock_timer_base
>>> schedule_timeout_uninterruptible
>>> msleep
>>> lock_device_hotplug_sysfs
>>> online_store
>>> dev_attr_store
>>> sysfs_write_file
>>> vfs_write
>>> SyS_write
>>> system_call_fastpath
>>>
>>> Last level cache shared map is built during cpu up and build sched domain
>>> routine takes advantage of it to setup sched domain cpu topology, however,
>>> llc shared map is unreleased during cpu disable which lead to invalid sched
>>> domain cpu topology. This patch fix it by release llc shared map correctly
>>> during cpu disable.
>>
>>Very little is said in this changelog about how the bug was
>>found, how likely it is to occur for others, what systems are
>>affected, etc.
>
>This bug can be triggered by hot add and remove large number of xen
>domain0's vcpus repeated.
>
If I need to send a new version of the patch or you can pick the patch
w/ the updated changelog for me? ;-)
Regards,
Wanpeng Li
>Regards,
>Wanpeng Li
>
>>
>>Thanks,
>>
>> Ingo
next prev parent reply other threads:[~2014-09-04 9:33 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-29 9:24 [PATCH v4] x86, hotplug: fix llc shared map unreleased during cpu hotplug Wanpeng Li
2014-07-29 17:18 ` Toshi Kani
2014-08-07 6:33 ` Wanpeng Li
[not found] ` <20140808224057.GA9288@oranje.fc.hp.com>
2014-08-15 3:00 ` Wanpeng Li
2014-08-15 6:07 ` Borislav Petkov
2014-08-25 5:32 ` Wanpeng Li
2014-09-04 1:46 ` Wanpeng Li
2014-09-04 5:20 ` Ingo Molnar
2014-09-04 5:40 ` Yasuaki Ishimatsu
2014-09-04 6:24 ` Peter Zijlstra
2014-09-04 9:02 ` Wanpeng Li
2014-09-04 8:56 ` Wanpeng Li
2014-09-04 9:34 ` Wanpeng Li [this message]
2014-09-15 1:32 ` Wanpeng Li
2014-09-16 9:01 ` Ingo Molnar
2014-09-16 10:00 ` Wanpeng Li
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