Re: Fwd: 2.6.26.3 kernel - progressive slowdown over NFS

["Ray Lee" <ray-lk@madrabbit.org>]

[ sigh, adding back original reporter. Oops.  -- rbl ]

Priyank Patel, please see Trond's response below and try out the
suggested patch linked below.

On Tue, Dec 9, 2008 at 5:06 PM, Trond Myklebust
<trond.myklebust@fys.uio.no> wrote:
> On Tue, 2008-12-09 at 16:38 -0800, Ray Lee wrote:
>> [ adding netdev, linux-nfs to cc: -- rbl ]
>>
>> Hi,
>>
>>
>> We have a simple python program which keeps running a C loop to lstat
>> NFS mounted directories.  We are seeing some weird behavior w.r.t. the
>> run-time of this program on 2.6.26.3 kernel vs 2.6.24 kernel.
>>
>> The run-time of the following code increases over time on the 2.6.26.3
>> kernel, whereas remains flat (as expected) on the 2.6.24 kernel.
>> [See attached graphs - B1.jpg and B2.jpg]  Once the 2.6.26.3 machine
>> gets into this state, we need to restart the box to get back to
>> reasonable run-times.  Is this a known issue ?
>
> Could you try applying the following patch?
>
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git&a=commitdiff&h=23918b03060f6e572168fdde1798a905679d2e06
>
> Trond
>
> PS: note that your 2.6.26 config file has _very_ different memory models
> and kernel debugging options enabled compared to your 2.6.24 kernel.
> That may also affect performance.
>
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