Re: [2.6.34-rc2 NFS4 oops] open error path failure...

[Chuck Lever]

On 03/31/2010 07:20 AM, Daniel J Blueman wrote:
> Talking of expensive, I see latencytop show>16000ms latency for
> writing pages when I have a workload that does large buffered I/O to
> an otherwise uncongested server. The gigabit network is saturated, and
> reads often stall for 1000-4000ms (!). Client has the default 16 TCP
> request slots, and server has 8 nfsds - the server is far from disk or
> processor-saturated. I'll see if there is any useful debugging I can
> get about this.

That latency is pretty much guaranteed to be due to a long RPC backlog 
queue on the client.  Bumping the size of the slot table to 128 and 
increasing the number of NFSD threads may help.

--
chuck[dot]lever[at]oracle[dot]com
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