Re: [PATCH] improve the performance of large sequential write NFS workloads

Martin Knoblauch
2009-12-22T13:08:30Z

----- Original Message ----

> From: Wu Fengguang <fengguang.wu@intel.com>
> To: Steve Rago <sar@nec-labs.com>
> Cc: Peter Zijlstra <peterz@infradead.org>; "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>; "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>; "Trond.Myklebust@netapp.com" <Trond.Myklebust@netapp.com>; jens.axboe <jens.axboe@oracle.com>
> Sent: Tue, December 22, 2009 2:59:07 AM
> Subject: Re: [PATCH] improve the performance of large sequential write NFS workloads
>

[big snip]

>
> In general it's reasonable to keep NFS per-file nr_dirty low, however
> questionable to do per-file nr_writeback throttling. This does not
> work well with the global limits - eg. when there are many dirty
> files, the summed-up nr_writeback will still grow out of control.
> And it's more likely to impact user visible responsiveness than
> a global limit. But my opinion can be biased -- me have a patch to
> do global NFS nr_writeback limit ;)
>

is that "NFS: introduce writeback wait queue", which you sent me a while ago and I did not test until now :-( ?

Cheers
Martin