Re: Error with NFS and XEN (High network load)

[Roberto Gonzalez Azevedo <rgonzalez@censanet.com.br>]

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Thanks !!! Now it's working !!! Dom0 and DomU don't crash anymore !!!
Please, report it on Xen Bugzilla id # 735.


Thanks !

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Roberto Gonzalez Azevedo


Herbert Xu wrote:
> On Tue, Aug 15, 2006 at 10:58:15PM +0000, Roberto Gonzalez Azevedo wrote:
>> On domU machine:
>> root@domU:# mount -t nfs real-machine-not-xen-or-any-virtual:/mnt /data
>> [ok]
>>
>> Crash:
>> root@domU:# time dd if=/dev/zero of=/data/test.txt bs=16k count=16384
>> [NOT OK]
> 
> Thanks for the report.  This is what I needed to reproduce the problem.
> I forgot to initialise the first fragment to a proper value in the first
> SG patch.
> 
> [NET] back: Initialise first fragment properly
> 
> The first fragment is used to store the pending_idx of the leading
> txreq if it doesn't fit in the head area.  When it does fit into
> the head we need to ensure that the first fragment contains a value
> that is not equal to pending_idx as that's what we use to distinguish
> between the two cases in a a number of places.
> 
> This patch sets the first fragment to ~0 which is not equal to any
> valid pending_idx.  Without this initialisation, we may double-free
> a pending_idx if the first fragment happened to contain a value
> equal to it (this usually happened with pending_idx 0).
> 
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> 
> Cheers,
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