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

Domain-0 CPU pinning - is it still a best practice?


  • To: xen-users@xxxxxxxxxxxxx
  • From: Andy Smith <andy@xxxxxxxxxxxxxx>
  • Date: Thu, 28 Jan 2021 14:46:48 +0000
  • Delivery-date: Thu, 28 Jan 2021 14:47:31 +0000
  • List-id: Xen user discussion <xen-users.lists.xenproject.org>
  • Openpgp: id=BF15490B; url=http://strugglers.net/~andy/pubkey.asc

Hello,

A lot of the information on
https://wiki.xenproject.org/wiki/Xen_Project_Best_Practices is very
old now (e.g. shows xm stack or commands that are no longer valid
for xl). Are people still dedicating CPU cores to dom0 in modern
versions of Xen with credit2 scheduler?

If I put this on the hypervisor command line:

    dom0_max_vcpus=2 dom0_vcpus_pin

how do I know which PCPUs dom0 will be pinned to?

I am aware that after boot I can:

# xl vcpu-pin Domain-0 0 0 -
# xl vcpu-pin Domain-0 1 1 -

to pin Domain-0 to PCPUs 0 and 1.

And then potentially set:

cpus = "all,^0,^1"

in every guest config to tell them to use "all PCPUs except 0 or 1",
thus leaving PCPUs 0 and 1 exclusively used by Domain-0.

Cheers,
Andy



 


Rackspace

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