WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] FreeBSD/Xen ugliness

I've seen the same timing issues. We do call yield where appropriate:

static void
cpu_idle_default(void)
{
#if 0
        /*
         * we must absolutely guarentee that hlt is the
         * absolute next instruction after sti or we
         * introduce a timing window.
         */
        __asm __volatile("sti; hlt");
#endif
        enable_intr();
        HYPERVISOR_yield();
}


So I'm not sure what the problem is. After the 5.3 work and coredump is
done I might look into it. There may have been some fixes to the clock
code in the meantime.


                                -Kip


On Sat, 8 Jan 2005, Derrik Pates wrote:

> Kip:
>
> Well, I have good news; thanks to Darren Tucker pointing out that the
> boot.netif.* parameters _have_ to be added, I was able to successfully
> boot your FreeBSD/Xen kernel. It seems to work okay so far. It fairly
> regularly (every few minutes or so) spits out a line like:
>
> Expensive timeout(9) function: 0xc00b0bd0(0) 0.010000854 s
>
> at me, but it seems to otherwise behave as FreeBSD should. The only
> thing I've noticed so far is that, looking at the output of 'xm list',
> its domain's virtual-time clock seems to grow at a constant rate. I'm
> guessing this means it doesn't call up to the hypervisor and say "Please
> schedule someone else, I'm idle right now" when it has nothing to do. It
> doesn't seem to affect the performance of other domains though, but I
> thought it worth pointing out. Unfortunately, I don't know enough about
> FreeBSD's scheduler to make the necessary changes to make this work as
> it should. I'll have to see about getting a proper full CVS pull of the
> sys/ tree for 5.2.1 on my FreeBSD install in VMware, and see if I can
> make a FreeBSD kernel build work; however, I'd like to see the 5.3
> kernel when you get around to it.
>
> --
> Derrik Pates
> dpates@xxxxxxxxxx
>


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel