Subject: Re: LFS and Xen3 testing
To: None <>
From: Jed Davis <>
List: current-users
Date: 09/12/2006 19:32:48 (YAMAMOTO Takashi) writes:

>> I've just recently discovered something interesting with Xen3 that
>> might be related: if the dom0 is running something that spins the CPU
>> (like "perl -e '1 while 1'" or "yes > /dev/null") the NetBSD domU will
>> not be run at all; it won't respond to the console nor to network
>> traffic, and its timer event handler won't be called.  A Linux domU
>> doesn't appear to have the same problem.
> it's a characteristic of the default setting of sedf scheduler.
> are you sure it doesn't happen for linux domU?

The Linux domU is definitely affected, but it's still able to answer
pings (if a bit slowly), while the NetBSD one doesn't answer any until
the dom0 stops hogging the CPU.

However, I see what you mean about the default scheduling parameters,
I think -- giving the domU a nonzero minimum timeslice fixes this.

(let ((C call-with-current-continuation)) (apply (lambda (x y) (x y)) (map
((lambda (r) ((C C) (lambda (s) (r (lambda l (apply (s s) l))))))  (lambda
(f) (lambda (l) (if (null? l) C (lambda (k) (display (car l)) ((f (cdr l))
(C k)))))))    '((#\J #\d #\D #\v #\s) (#\e #\space #\a #\i #\newline)))))