Re: Dom0 starvs DomU

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sun, Nov 15, 2015 at 08:15:43PM +0100, Torbjörn Granlund wrote:
> Manuel Bouyer <bouyer%antioche.eu.org@localhost> writes:
> 
>   This did give me an idea, and I think I found a bug in the xbd backend.
>   It looks like the kernel thread is created with the wrong priority.
>   Could you try the attached patch ?
>   
>   I could reproduce the problem creating a small loop around a syscall in dom0,
>   and the attached patch fixes the issue for me.
> 
> I put NetBSD 7-STABLE on a system (AMD K10 Thuban w 32 GiB RAM, high-end
> SSD), pulled in 7-STABLE sources, applied your patch, built XEN3_DOM0,
> and copied the newly compiled ./netbsd to /netbsd-XEN3_DOM0.
> 
> Before your patch, a ssh to a DomU on the system would time out every
> time before I got in, if Dom0 is loaded by a compile.  With the patch, I
> can log into a DomU with less than 1 s of delay.  It is even possible to
> do an "ls -R /" without hangs...
> 
> Thanks, this should allow me to use a NetBSD Dom0!

thanks for testing. This is commited to -HEAD, I will request a pullup
to netbsd-7 and netbsd-6

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--