Re: Block IO Controller V4

[Vivek Goyal]

On Mon, Dec 07, 2009 at 04:45:49PM +0800, Gui Jianfeng wrote:
> Vivek Goyal wrote:
> > On Thu, Dec 03, 2009 at 01:10:03PM -0500, Vivek Goyal wrote:
> > 
> > [..]
> >> Hi Gui,
> >>
> >> Can you please try following patch and see if it helps you. If not, then
> >> we need to figure out why we choose to not idle and delete the group from
> >> service tree.
> >>
> > 
> > Hi Gui,
> > 
> > Please try this version of the patch instead of previous one. During more
> > testing I saw some additional deletions where we should have waited and
> > the reason being that we were hitting boundary condition. At the request
> > completion time slice has not expired but after 4-5 ns, select_queue hits
> > and jiffy has incremented by then and slice expires.
> > 
> > ttime_mean, is not covering this condition because this workload is so
> > sequential that ttime_mean=0.
> > 
> > So I am checking for new condition where if we are into last ms of slice,
> > mark the queue wait_busy.
> > 
> > Thanks
> > Vivek
> > 
> > Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> 
> Hi, Vivek
> 
> I add some debug message in select_queue, it does meet the boundary condition. 
> I tried this patch, and works fine on my box.
> 
> Acked-by: Gui Jianfeng <guijiafneng@xxxxxxxxxxxxxx>

Thanks Gui, I will send this patch to Jens in a separate mail.

Thanks
Vivek
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