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From: Alex Bligh <alex@alex.org.uk>
To: Joe Jin <joe.jin@oracle.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	Frank Blaschka <frank.blaschka@de.ibm.com>,
	"David S. Miller" <davem@davemloft.net>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	zheng.x.li@oracle.com, Xen Devel <xen-devel@lists.xen.org>,
	Ian Campbell <Ian.Campbell@citrix.com>,
	Jan Beulich <JBeulich@suse.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Alex Bligh <alex@alex.org.uk>
Subject: Re: kernel panic in skb_copy_bits
Date: Mon, 01 Jul 2013 09:29:02 +0100	[thread overview]
Message-ID: <A8CFF199DB41859580D3A04A@Ximines.local> (raw)
In-Reply-To: <51D0F514.3070309@oracle.com>

Joe,

> Do you know if have a fix for above? so far we also suspected the
> grant page be unmapped earlier, we using 4.1 stable during our test.

A true fix? No, but I posted a patch set (see later email message
for a link) that you could forward port. The workaround is:

>> A workaround is to turn off O_DIRECT use by Xen as that ensures
>> the pages are copied. Xen 4.3 does this by default.
>>
>> I believe fixes for this are in 4.3 and 4.2.2 if using the
>> qemu upstream DM. Note these aren't real fixes, just a workaround
>> of a kernel bug.
>
> The guest is pvm, and disk model is xvbd, guest config file as below:
...
> I think this only for pvhvm/hvm?

I don't have much experience outside pvhvm/hvm, but I believe it
should work for any device.

Testing was simple - just find all (*) the references to O_DIRECT
in your device model and remove them!

(*)=you could be less lazy than me and find the right ones.

I am guessing it will be the same ones though.

-- 
Alex Bligh

      parent reply	other threads:[~2013-07-01  8:29 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-27  2:58 kernel panic in skb_copy_bits Joe Jin
2013-06-27  5:31 ` Eric Dumazet
2013-06-27  7:15   ` Joe Jin
2013-06-28  4:17   ` Joe Jin
2013-06-28  6:52     ` Eric Dumazet
2013-06-28  9:37       ` Eric Dumazet
2013-06-28 11:33         ` Joe Jin
2013-06-28 23:36         ` Joe Jin
2013-06-29  7:04           ` Eric Dumazet
2013-06-29  7:20           ` Eric Dumazet
2013-06-29 16:11             ` Ben Greear
2013-06-29 16:26               ` Eric Dumazet
2013-06-29 16:31                 ` Ben Greear
2013-06-30  0:26             ` Joe Jin
2013-06-30  7:50               ` Eric Dumazet
2013-07-01 20:36         ` David Miller
2013-06-30  9:13     ` Alex Bligh
2013-06-30  9:35       ` Alex Bligh
2013-07-01  3:18       ` Joe Jin
2013-07-01  8:11         ` Ian Campbell
2013-07-01 13:00           ` Joe Jin
2013-07-04  8:55           ` Joe Jin
2013-07-04  8:59             ` Ian Campbell
2013-07-04  9:34               ` Eric Dumazet
2013-07-04  9:52                 ` Ian Campbell
2013-07-04 10:12                   ` Eric Dumazet
2013-07-04 12:57                     ` Alex Bligh
2013-07-04 21:32                     ` David Miller
2013-07-01  8:29         ` Alex Bligh [this message]

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