2008-08-31 19:30:50

by J. Bruce Fields

[permalink] [raw]
Subject: Re: NFS regression? Odd delays and lockups accessing an NFS export.

On Sat, Aug 30, 2008 at 04:47:41PM +0100, Ian Campbell wrote:
> On Wed, 2008-08-27 at 09:43 -0500, Tom Tucker wrote:
> > Sure. I've actually tried to reproduce it here unsuccessfully.
> >
> > As a starter, I would suggest turning on transport debugging:
> >
> > # echo 256 > /proc/sys/sunrpc/rpc_debug
> > [...]
> > If Ian is willing to create the log (or already has one), I'm
> > certainly willing to look at it.
>
> It produced only the following (is that what was expected?):
>
> [146866.448112] -pid- proc flgs status -client- -prog- --rqstp- -timeout -rpcwait -action- ---ops--
> [146866.448112] 30576 0001 00a0 0 f77a1600 100003 f7903340 15000 xprt_pending fa0ba88e fa0c9df4
> [146866.448112] 30577 0004 0080 -11 f77a1600 100003 f7903000 0 xprt_sending fa0ba88e fa0c9df4

It's normal to get something like that when you turn it on, yes (unless
someone else spots anything odd about that...) but what's really needed
is to turn this on and then reproduce the problem--it's the debugging
output that goes to the logs during the problem that'll be interesting.

--b.


2008-08-31 19:44:14

by Ian Campbell

[permalink] [raw]
Subject: Re: NFS regression? Odd delays and lockups accessing an NFS export.

On Sun, 2008-08-31 at 15:30 -0400, J. Bruce Fields wrote:
> On Sat, Aug 30, 2008 at 04:47:41PM +0100, Ian Campbell wrote:
> > On Wed, 2008-08-27 at 09:43 -0500, Tom Tucker wrote:
> > > Sure. I've actually tried to reproduce it here unsuccessfully.
> > >
> > > As a starter, I would suggest turning on transport debugging:
> > >
> > > # echo 256 > /proc/sys/sunrpc/rpc_debug
> > > [...]
> > > If Ian is willing to create the log (or already has one), I'm
> > > certainly willing to look at it.
> >
> > It produced only the following (is that what was expected?):
> >
> > [146866.448112] -pid- proc flgs status -client- -prog- --rqstp- -timeout -rpcwait -action- ---ops--
> > [146866.448112] 30576 0001 00a0 0 f77a1600 100003 f7903340 15000 xprt_pending fa0ba88e fa0c9df4
> > [146866.448112] 30577 0004 0080 -11 f77a1600 100003 f7903000 0 xprt_sending fa0ba88e fa0c9df4
>
> It's normal to get something like that when you turn it on, yes (unless
> someone else spots anything odd about that...) but what's really needed
> is to turn this on and then reproduce the problem--it's the debugging
> output that goes to the logs during the problem that'll be interesting.

That's what I did. The first time I did the echo I just got the header
line, then I waited for the repro and since there had been no further
logging I ran the echo again and got the three lines above.

Sounds like you expected there to be more and ongoing logging?

Ian.

> --b.
>
--
Ian Campbell

kernel, n.:
A part of an operating system that preserves the medieval
traditions of sorcery and black art.


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