[Lxc-users] blkio.weight doesn't work

[陈竞]

thank you very much.  I really get it

2011/12/14 Zhu Yanhai <zhu.yanhai at gmail.com>

> 在 2011年12月14日 下午5:30，陈竞 <cj.magina at gmail.com> 写道：
> > i got the problem, my script is wrong, it should drop the cache, or it
> will
> > read data from cache,
> >  the script is :
> > sync
> > echo 3 > /proc/sys/vm/drop_caches
> > dd if=/tmp/file1 of=/dev/null
> >
> >
> > size of file1 is 400M, and i get new test result:
> > A: blkio.weight=100    cost 11.12s   speed is 37.5MB/s
> > B: blkio.weight=1000    cost 6.4s   speed is 65.7MB/s
> >
> > so the blkio.weight has some effect, bu the result is not as good as 1:10
>
> No, it is good.
> Blkio controller doesn't reserve bandwith for any groups, so what
> happened in your test is Group B finished before Group A, and after
> that Group A was able to occupy all bandwith, which made it much
> faster.
> So if the size of input files are the same, then the expect run time is:
> For Group B: Runtime A = size / 10B
> For Group A: Runtiem B = size / 10B + 0.9 * size / 11B
> Then Runtime A / Runtime B = 0.55
>
> In your test, 6.4 / 11.12 = 0.5755, so it works well.
>
> --
> Thanks,
> Zhu Yanhai
>
>
> >
> >
> > 2011/12/14 Zhu Yanhai <zhu.yanhai at gmail.com>
> >>
> >> And neither slice_idle nor group_idle is zero? Did you change any
> >> default parameters for CFQ?
> >>
> >> -zyh
> >>
> >> 在 2011年12月14日 下午4:55，陈竞 <cj.magina at gmail.com> 写道：
> >> > my io scheduler is CFQ.... So the result is weird
> >> >
> >> > 在 2011年12月14日 下午4:12，陈竞 <cj.magina at gmail.com>写道：
> >> >
> >> >> Hi， i'm using lxc in my project, i want to control disk io speed, so
> i
> >> >> use
> >> >> blkio.weight. I test it, but the result is confusing.
> >> >> I create two container A and B:
> >> >> A: blkio.weight = 100            B : blkio.weight=1000
> >> >>
> >> >> the running process in A and B are the same, which is bash script :
> >> >> dd if=/tmp/xxx of=/dev/null
> >> >> the size of xxx is 400Mb
> >> >>
> >> >> I suppose that A would be slower than B, since its weight is small,
> >> >> while
> >> >> the test turns out that B run as fast as A, they are in same speed.
> >> >> Can any help me figure it out ?
> >> >> PS: my kernel is 2.6.32, and lxc is 0.7.5
> >> >> --
> >> >> 陈竞，中科院计算技术研究所，高性能计算机中心
> >> >> Jing Chen HPCC.ICT.AC China
> >> >
> >> >
> >> >
> >> >
> >> > --
> >> > 陈竞，中科院计算技术研究所，高性能计算机中心
> >> > Jing Chen HPCC.ICT.AC China
> >> >
> >> >
> >> >
> ------------------------------------------------------------------------------
> >> > Cloud Computing - Latest Buzzword or a Glimpse of the Future?
> >> > This paper surveys cloud computing today: What are the benefits?
> >> > Why are businesses embracing it? What are its payoffs and pitfalls?
> >> > http://www.accelacomm.com/jaw/sdnl/114/51425149/
> >> > _______________________________________________
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> >> > Lxc-users at lists.sourceforge.net
> >> > https://lists.sourceforge.net/lists/listinfo/lxc-users
> >> >
> >
> >
> >
> >
> > --
> > 陈竞，中科院计算技术研究所，高性能计算机中心
> > Jing Chen HPCC.ICT.AC China
>



-- 
陈竞，中科院计算技术研究所，高性能计算机中心
Jing Chen HPCC.ICT.AC China
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