linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Wanpeng Li <wanpeng.li@linux.intel.com>
To: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@kernel.org>,
	Wanpeng Li <wanpeng.li@linux.intel.com>,
	hpa@zytor.com, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	x86@kernel.org, Borislav Petkov <bp@alien8.de>,
	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>
Subject: Re: [PATCH v4] x86, hotplug: fix llc shared map unreleased during cpu hotplug
Date: Thu, 4 Sep 2014 17:02:25 +0800	[thread overview]
Message-ID: <20140904090225.GA6555@kernel> (raw)
In-Reply-To: <5407FB37.2070306@jp.fujitsu.com>

On Thu, Sep 04, 2014 at 02:40:07PM +0900, Yasuaki Ishimatsu wrote:
>(2014/09/04 14:20), 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.
>
>Hi Wanpeng,

Hi Yasuaki,

>
>In my understanding, the panic occurs by just onlining CPU as follows:
>echo 1 > /sys/devices/system/cpu/cpuX/online
>

See my reply to Ingo.

Regards,
Wanpeng Li 

>So, how about add the information?
>
>Thanks,
>Yasuaki Ishimatsu
>
>
>>
>>Thanks,
>>
>>	Ingo
>>
>

  parent reply	other threads:[~2014-09-04  9:01 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 [this message]
2014-09-04  8:56   ` Wanpeng Li
2014-09-04  9:34     ` Wanpeng Li
2014-09-15  1:32       ` Wanpeng Li
2014-09-16  9:01       ` Ingo Molnar
2014-09-16 10:00         ` Wanpeng Li

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140904090225.GA6555@kernel \
    --to=wanpeng.li@linux.intel.com \
    --cc=bp@alien8.de \
    --cc=hpa@zytor.com \
    --cc=isimatu.yasuaki@jp.fujitsu.com \
    --cc=jan.kiszka@siemens.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=prarit@redhat.com \
    --cc=rientjes@google.com \
    --cc=srostedt@redhat.com \
    --cc=toshi.kani@hp.com \
    --cc=x86@kernel.org \
    --cc=yang.z.zhang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).