Re: [PATCH v3 0/7] CFS Bandwidth Control

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

On Wed, Nov 17, 2010 at 04:32:29PM +0800, Lai Jiangshan wrote:
> On 10/12/2010 03:49 PM, Bharata B Rao wrote:
> > Hi,
> > 
> > Its been a while since we posted CPS hard limits (aka CFS bandwidth control
> > now) patches, hence a quick recap first:
> > 
> > - I have been working on CFS hard limits since last year and have posted
> >   a few versions of the same (last post: http://lkml.org/lkml/2010/1/5/44)
> > - Paul Turner and Nikhil Rao meanwhile started working on CFS bandwidth
> >   control and have posted a couple of versions.
> >   (last post v2: http://lwn.net/Articles/385055/)
> > 
> 
> Hi, All
> 
> 	I tried it, it works very good! It adds a very useful feature.
> It is very helpful for virtualization or cloud-computing I think.
> I hope the next version patchset of it will be sent and get merged soon.
> 
> When I tested it, my box became dead several times, infrequently, and
> I don't know how to reproduce it, but next steps may help to reproduce it:
> 
> # mount -t cgroup -o cpu xxx /mnt
> # cd /mnt
> # mkdir test
> # cd test
> # echo 5000000 > cpu.cfs_period_us
> # echo 1000000 > cpu.cfs_quota_us
> # cat /dev/zero > /dev/null &
> # echo $! > tasks
> # #make the system busy, browse websites and open many tabs in your browser etc
> # #but do NOT do things important.
> # #after some time, the system may dead. (can not respond even you type AltSysrqC)
> 

Hi Lai, Thanks for testing the patches. I haven't seen this behaviour still.
But will try out the steps you mention and see if I can reproduce it here.
Meanwhile if you find more information about the problem, do let us know.

Regards,
Bharata.