2009-09-02 01:00:03

by Gui, Jianfeng/归 剑峰

Subject: Re: [RFC] IO scheduler based IO controller V9

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%

2009-09-02 13:46:03

by Vivek Goyal

Subject: Re: [RFC] IO scheduler based IO controller V9

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

2009-09-07 02:15:42

by Gui, Jianfeng/归 剑峰

Subject: Re: [RFC] IO scheduler based IO controller V9

Hi Vivek,

Here is the vanilla kernel and V9 comparision.

Normal Read | Random Read | Normal Write | Random Write

vanilla(Avg of 3 times) 67580 KiB/s 3540 KiB/s 61964 KiB/s 9823 KiB/s

V9(Avg of 3 times) 68954 KiB/s 3567 KiB/s 60654 KiB/s 9858 KiB/s

Performance +2.0% +0.7% -2.1% +0.3%

2009-09-08 13:57:19

by Vivek Goyal

Subject: Re: [RFC] IO scheduler based IO controller V9

On Mon, Sep 07, 2009 at 10:14:06AM +0800, Gui Jianfeng wrote:
> Hi Vivek,
>
> Here is the vanilla kernel and V9 comparision.
>
> Normal Read | Random Read | Normal Write | Random Write
>
> vanilla(Avg of 3 times) 67580 KiB/s 3540 KiB/s 61964 KiB/s 9823 KiB/s
>
> V9(Avg of 3 times) 68954 KiB/s 3567 KiB/s 60654 KiB/s 9858 KiB/s
>
> Performance +2.0% +0.7% -2.1% +0.3%
>

Thanks Gui. So that's lot of improvements from previous versions. I remember
you were noticing 7% regressions in buffered write performance.

Thanks
Vivek