From: Joerg Roedeljoro <joro@8bytes.org>
To: 范冬冬 <fandd@inspur.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
"jiang.liu@intel.com" <jiang.liu@intel.com>,
iommu <iommu@lists.linux-foundation.org>,
闫晓峰 <yanxiaofeng@inspur.com>, 刘长生 <liuchangsheng@inspur.com>
Subject: Re: Panic when cpu hot-remove
Date: Wed, 17 Jun 2015 13:52:39 +0200 [thread overview]
Message-ID: <20150617115238.GC27750@8bytes.org> (raw)
In-Reply-To: <42BB8332972FC149B81C55A0D41E3A79C07469@jtjnmailbox06.home.langchao.com>
On Wed, Jun 17, 2015 at 10:42:49AM +0000, 范冬冬 wrote:
> Hi maintainer,
>
> We found a problem that a panic happen when cpu was hot-removed. We also trace the problem according to the calltrace information.
> An endless loop happen because value head is not equal to value tail forever in the function qi_check_fault( ).
> The location code is as follows:
>
>
> do {
> if (qi->desc_status[head] == QI_IN_USE)
> qi->desc_status[head] = QI_ABORT;
> head = (head - 2 + QI_LENGTH) % QI_LENGTH;
> } while (head != tail);
Hmm, this code interates only over every second QI descriptor, and tail
probably points to a descriptor that is not iterated over.
Jiang, can you please have a look?
Joerg
next prev parent reply other threads:[~2015-06-17 11:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-17 10:42 Panic when cpu hot-remove 范冬冬
2015-06-17 11:52 ` Joerg Roedeljoro [this message]
2015-06-17 14:36 ` Alex Williamson
2015-06-18 5:40 ` Jiang Liu
[not found] ` <558272E3.4000504@inspur.com>
2015-06-18 7:54 ` fandongdong
2015-06-25 8:11 ` Jiang Liu
2015-06-25 10:46 ` fandongdong
2015-11-09 20:21 ` Guenter Roeck
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