[nfs] process locks in "bo_wwait" on 6.4

[pluknet]

2009/6/29 Attilio Rao <attilio at freebsd.org>:
> 2009/6/29 pluknet <pluknet at gmail.com>:
>> 2009/6/29 Attilio Rao <attilio at freebsd.org>:
>>> 2009/6/29 pluknet <pluknet at gmail.com>:
>>>> 2009/6/29 Attilio Rao <attilio at freebsd.org>:
>>>>> 2009/6/29 pluknet <pluknet at gmail.com>:
>>>>>> 2009/6/26 pluknet <pluknet at gmail.com>:
>>>>>>> 2009/6/26 pluknet <pluknet at gmail.com>:
>>>>>>>> Hello.
>>>>>>>>
>>>>>>>> While building a module on nfs mounted /usr/src
>>>>>>>> I got an unkillable process waiting forever in bo_wwait.
>>>>>>>
>>>>>>> Small note: iface on NFS server has mtu changed from 1500 to 1450.
>>>>>>> Can this be a source of the problem?
>>>>>>
>>>>>> This is 100% reproducible. Lock in the same place. Any hints?
>>>>>
>>>>> Can you also show the value of ps?
>>>>> A precise map of what processes are doing would give an help.
>>>>> Also would be useful to printout traces for other threads and not only
>>>>> the stucked one.
>>>>>
>>>>
>>>> >From another run:
>>>
>>> I'm unable to see who would be locking the buffer object in question.
>>> Do you have INVARIANT_SUPPORT/INVARIANTS on?
>>
>> Yes, I do both.
>>
>>> What revision of /usr/src/sys/kern/vfs_bio.c are you running with?
>>>
>>
>> As of 6.4-R: CVS rev 1.491.2.12.4.1 / SVN rev 183531.
>
> Please try this patch and report.
>
> Thanks,
> Attilio
>
> --- src/sys/nfsclient/nfs_vnops.c       2008/02/13 20:44:18     1.281
> +++ src/sys/nfsclient/nfs_vnops.c       2008/03/22 09:15:15     1.282
> @@ -33,7 +33,7 @@
>  */
>
>  #include <sys/cdefs.h>
> -__FBSDID("$FreeBSD:
> /usr/local/www/cvsroot/FreeBSD/src/sys/nfsclient/nfs_vnops.c,v 1.281
> 2008/02/13 20:44:18 attilio Exp $");
> +__FBSDID("$FreeBSD:
> /usr/local/www/cvsroot/FreeBSD/src/sys/nfsclient/nfs_vnops.c,v 1.282
> 2008/03/22 09:15:15 jeff Exp $");
>

Do you refer to the whole svn r177493, or is its nfs part will be enough?
This only vfs_vnops.c diff seems not applicable without underneath
kernel part changes.

I'll try. Thanks.

-- 
wbr,
pluknet