ruk.ansari

[Rukhsana Ansari]

http://vinco.be/uhrbc/iok.lfwriaklbdxsdgbr





ruk.ansari


7/21/2013 6:38:18 AM
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] virtio: Use ioeventfd for virtqueue notify

[rukhsana ansari]

Hi,

W.r.t:
 Note that this is a tradeoff.  If an idle core is available and the
 scheduler places the iothread on that core, then the heavyweight exit is
 replaced by a lightweight exit + IPI.  If the iothread is co-located with
 the vcpu, then we'll take a heavyweight exit in any case.

Q: Does the kvm kernel code check for such a condition and take a
heavyweight exit?

 The first case is very likely if the host cpu is undercommitted and there is
 heavy I/O activity.  This is a typical subsystem benchmark scenario (as
 opposed to a system benchmark like specvirt).  My feeling is that total
 system throughput will be decreased unless the scheduler is clever enough to
 place the iothread and vcpu on the same host cpu when the system is
 overcommitted.


Q: Sorry if the answer is obvious here.
If the heavyweight exit is taken when both threads are assigned to the
same core, how will the system throughput increase?


Thanks
Rukhsana
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: vhost-net unreleased?

[rukhsana ansari]

In case, it helps, vhost functionality has been patched into and
available in the src rpm -
qemu-0.12.3-8.fc13.src.rpm
at
http://rpm.pbone.net/index.php3/stat/4/idpl/14076054/dir/fedora_13/com/qemu-system-x86-0.12.3-8.fc13.x86_64.rpm.html


On Fri, Aug 20, 2010 at 1:49 AM, John Bellessa belle...@illinois.edu wrote:

 On Tue, Aug 17, 2010 at 3:13 AM, Avi Kivity a...@redhat.com wrote:
   On 08/17/2010 09:58 AM, Christian Theune wrote:
 
  Hi,
 
  I've been plugging through code and presentations trying to find out
  whether the KVM/qemu side of vhost-net has been released yet. The git
  archive seems to include the vhost-net code since about a year already, but
  I could not find any trace of it in 0.12.5.
 
  Can you confirm, that vhost-net on the kvm/qemu side is not released yet?
  And if it is so, does anyone have a gut feeling of when it will be?
 
  vhost-net will be supported by qemu-kvm 0.13 which is on track for release
  soon.
 
  --
  error compiling committee.c: too many arguments to function
 
  --
  To unsubscribe from this list: send the line unsubscribe kvm in
  the body of a message to majord...@vger.kernel.org
  More majordomo info at  http://vger.kernel.org/majordomo-info.html
 

 I'm a little confused.  The vhost-net page
 (http://www.linux-kvm.org/page/VhostNet) indicates that it is fully
 functional.  Could you clarify that a bit?

 Thanks.
 --
 To unsubscribe from this list: send the line unsubscribe kvm in
 the body of a message to majord...@vger.kernel.org
 More majordomo info at  http://vger.kernel.org/majordomo-info.html



--
-Rukhsana
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html