[dm-devel] Re: [RFC] IO scheduler based IO controller V9

[Vivek Goyal <vgoyal redhat com>]

On Wed, Sep 02, 2009 at 08:58:38AM +0800, Gui Jianfeng wrote:
> Vivek Goyal wrote:
> > Hi All,
> > 
> > Here is the V9 of the IO controller patches generated on top of 2.6.31-rc7.
> > 
> > For ease of patching, a consolidated patch is available here.
> > 
> > http://people.redhat.com/~vgoyal/io-controller/io-scheduler-based-io-controller-v9.patch
> > 
> > Changes from V8
> > ===============
> > - Implemented bdi like congestion semantics for io group also. Now once an
> >   io group gets congested, we don't clear the congestion flag until number
> >   of requests goes below nr_congestion_off.
> > 
> >   This helps in getting rid of Buffered write performance regression we
> >   were observing with io controller patches.
> > 
> >   Gui, can you please test it and see if this version is better in terms
> >   of your buffered write tests.
> 
> Hi Vivek,
> 
> Here are some performance numbers generated by fio test. It seems V9 performance is better
> than V8 especially for write case.
> 
>                          Normal Read  |  Random Read  |  Normal Write  |  Random Write
> 
> V8(Avg of 3 timers)      64667 KiB/s     3387 KiB/s      59197 KiB/s      9327 KiB/s 
> 
> V9(Avg of 3 timers)      65947 KiB/s     3528 KiB/s      61654 KiB/s      9744 KiB/s
> 
> Performance              +2.0%           +4.1%           +4.2%            +4.5%

Thanks Gui. I was also keen to know how does the vanilla kernel and V9
comparision look like? Can you please run the same tests with vanilla
kernel also?

Thanks
Vivek