Comment 19 for bug 2012763

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Sergio Durigan Junior (sergiodj) wrote :

Jeff et al,

I worked to create new machine types for Jammy which support up to 1024 CPUs, which is exactly what the upstream patch pointed to by Jeff does. We decided to implement this via new machine types because, as Christian said, it is not entirely clear what kind of side effects this (apparent simple) setting can have, and also (perhaps most importantly) because it is much easier to justify SRUing such change if it's as contained as possible.

You can find a PPA with the proposed change here:

The qemu version is 1:6.2+dfsg-2ubuntu6.16~ppa2. The new machine types are named:

pc-i440fx-jammy-maxcpus Ubuntu 22.04 PC (i440FX + PIIX, maxcpus=1024, 1996)
pc-i440fx-jammy-hpb-maxcpus Ubuntu 22.04 PC (i440FX + PIIX +host-phys-bits=true, maxcpus=1024, 1996)
pc-q35-jammy-maxcpus Ubuntu 22.04 PC (Q35 + ICH9, maxcpus=1024, 2009)
pc-q35-jammy-hpb-maxcpus Ubuntu 22.04 PC (Q35 + ICH9, +host-phys-bits=true, maxcpus=1024, 2009)

Would it be possible for you to give this a try and let me know if it works? I still don't have access to a machine with that number of CPUs, so the amount of testing I can do is limited.