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/
Home Products Support Community News


RE: [Xen-devel] Interrupt levels

To: "Nicholas Lee" <nic-lists@xxxxxxxxxxxxxx>, "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>
Subject: RE: [Xen-devel] Interrupt levels
From: "Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>
Date: Tue, 8 Mar 2005 11:07:53 -0000
Cc: <xen-devel@xxxxxxxxxxxxxxxxxxxxx>, <ian.pratt@xxxxxxxxxxxx>, <ian.pratt@xxxxxxxxxxxx>
Delivery-date: Tue, 08 Mar 2005 11:08:43 +0000
Envelope-to: xen+James.Bulpin@xxxxxxxxxxxx
List-archive: <http://sourceforge.net/mailarchive/forum.php?forum=xen-devel>
List-help: <mailto:xen-devel-request@lists.sourceforge.net?subject=help>
List-id: List for Xen developers <xen-devel.lists.sourceforge.net>
List-post: <mailto:xen-devel@lists.sourceforge.net>
List-subscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=subscribe>
List-unsubscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=unsubscribe>
Sender: xen-devel-admin@xxxxxxxxxxxxxxxxxxxxx
Thread-index: AcUjw5oudFuT9hu5QriYidrWDs4+5gACzm5w
Thread-topic: [Xen-devel] Interrupt levels
> > This can happen if you block/unblock very frequently. The timer 
> > interrupt from Xen isn't entirely tick-based -- you also 
> get a timer 
> > interrupt every time you are rescheduled.
> By block/unblock I assume you mean context switching between different
> domains. Is this level normal? Is there a method to track down exactly
> is causing the block/unblocking?
> > So the large number of timer interrupts indicates lots of 
> unblocking. 
> > Really we should hold-off the timer interrupt if the domain was 
> > descheduled for less than a jiffy. :-)
> Is there a way to fix this at the moment?

Since processing timer interrupts are cheap there's no urgent fix
The real question is why are you blocking/unblocking at a rate of

What are your domains doing? What interrupt rates do they see?


SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
Xen-devel mailing list