Re: [PATCH] readahead:add blk_run_backing_dev

KOSAKI Motohiro
2009-05-27T02:34:53Z

> >> >even consumed 9% of a CPU, so where on earth has the kernel gone to?
> >> >
> >> >Have you been able to reproduce this in your testing?
> >>
> >> Yes, this test on my environment is reproducible.
> >
> >Hisashi, does your environment have some special configurations?
>
> Hi.
> My testing environment is as follows:
> Hardware: HP DL580
> CPU:Xeon 3.2GHz *4 HT enabled
> Memory:8GB
> Storage: Dothill SANNet2 FC (7Disks RAID-0 Array)
>
> I did dd to this disk-array and got improved performance number.
>
> I noticed that when a disk is just one HDD, performance improvement
> is very small.

thas's odd.

Why your patch depend on transfer rate difference?