[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] Question Also regarding interrupt balancing


  • To: "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>
  • From: harish <mvharish@xxxxxxxxx>
  • Date: Mon, 12 Jun 2006 12:05:24 -0700
  • Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
  • Delivery-date: Mon, 12 Jun 2006 12:05:48 -0700
  • Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=Q5p7MTbofw67D3Vdxb82uEMAU+9lnAkVchkTlLvXi1k6JfWGaBnyjl4L3z8837BHUc1z3ZbLhiOiq5w301dkJY0CsHLZBSYGtOAaAY5WhaGj1SncUz8w7gvqBWGxgE1DYJvwwH6T4XUhlZICt7TMs7GJTyaf1f1MpdQNXTVU7mc=
  • List-id: Xen developer discussion <xen-devel.lists.xensource.com>

Hi Keir,
Thanks a lot. I shall sync up to the latest unstable then. Shall keep you posted on how it goes.

thanks
harish

On 6/11/06, Keir Fraser <Keir.Fraser@xxxxxxxxxxxx> wrote:

On 10 Jun 2006, at 17:58, harish wrote:

>  echo "2" > /proc/irq/23/smp_affinity does not seem to change the
> value in smp_affinity
>  cat /proc/irq/23/smp_affinity still shows 0f
>
>  Could there some bug or configuration problem that you can think of?

It was a bug, which I've just fixed in -unstable and -testing staging
trees. When that reaches the public trees you should find that writing
to smp_affinity has the usual effect, but note:
  1. As when running on native, a request to change affinity is not
processed until the next interrupt occurs for that irq. If the
interrupt rate on that irq is very low, you may be able to observe old
value in smp_affinity before it is changed.
  2. You cannot change affinity of CPU-local interrupts (timer, resched,
callfunc). Requests to do so are silently ignored.
  3. If you try to set a multi-cpu cpumask for affinity, it will be
changed to a single-cpu cpumask automatically. Linux-on-Xen does not
automatically balance irq load across cpus -- that has to be done by a
user-space daemon (e.g., irqbalance).

  -- Keir


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.