Re: [GIT/PATCH 0/5] Re: unfair servicing of DomU vbd requests

[John Weekes <lists.xen@nuclearfallout.net>]

On 3/3/2011 9:09 AM, Ian Campbell wrote:
> On Thu, 2011-03-03 at 08:30 +0000, Keir Fraser wrote:
>> >  Without the round-robin servicing, unfairness to the point of starvation is
>> >  a distinct possibility.
> Indeed. The following is a forward port of these patches from
> 2.6.18-xen.hg:

Thanks for working on this, Ian.

I think that this has affected me several times, as I've noticed these 
symptoms before (heavy disk access by a few domains, followed by several 
Windows domUs mysteriously rebooting) -- as recently as Wednesday, in 
fact. The I/O from rebooting domUs, unfortunately, makes everything even 
worse, often leading to further Windows domUs crashing.

I look forward to this being merged into stable-2.6.32. In the meantime, 
I'll monkey around with git as you described and try to get a local 
version working. I'm itching to test it out, since this also might 
explain some of the occasional the longish disk delays that I see on 
machines with a medium I/O load (in which the dom0 still responds 
normally, but one of the domUs frequently stalls waiting for I/O).

-John