Re: [libvirt] [PATCH 0/6 v3] Add blkio cgroup support
Dominik Klein wrote:
> Hmm.. "blkio.weight" is used to control the Minimal
Maximal Bandwidth. If you'd like
> to control Max bandwidth to let your guests become I/O hungery.
"blkio.throttle.*"
> should helps. But these tunables aren't supported by blkiotune for the time
being.
> I'm considering to implement them in the future.
Hm, maybe I was not clear then. Let me try to rephrase.
As far as I understand, and as far as I saw during my tests, the blkio
controller only works for sync I/O requests (eg dd with oflag=direct).
Buffered I/O is not part of the control.
Yes, you are right.
And since a VM's I/O is most likely buffered in some fashion, this does
not have any effect. That's what my tests showed.
how about the start Guest with option "cache=none" to bypass pagecache?
This should help i think.
Did your tests show something different? Maybe I did things wrong then.
I think blkio cgroup should work if "cache=none" is set. But I didn't try
it,
Will try it later.
Thanks
Gui
Regards
Dominik
--
Regards
Gui Jianfeng