Re: NFS client latencies

Ingo Molnar
2005-03-31T14:51:55Z

* Ingo Molnar <mingo@elte.hu> wrote:

> > So the overhead you are currently seeing should just be that of
> > iterating through the list, locking said requests and adding them to
> > our private list.
>
> ah - cool! This was a 100 MB writeout so having 3.7 msecs to process
> 20K+ pages is not unreasonable. To break the latency, can i just do a
> simple lock-break, via the patch below?

with this patch the worst-case latency during NFS writeout is down to 40
usecs (!).

Lee: i've uploaded the -42-05 release with this patch included - could
you test it on your (no doubt more complex than mine) NFS setup?

Ingo