On 09/02/2022 10:31, Jane Malalane wrote: > This is not a bug. The xen cmdline can request both a NUMA restriction > and a vcpu count restriction for Dom0. The node restriction wil always > be respected which might mean either using dom0_max_vcpus < > opt_dom0_max_vcpus_max or using more vCPUs than pCPUs on a node. In > the case where dom0_max_vcpus gets capped at the maximum number of > pCPUs for the number of nodes chosen, it can be useful particularly > for debugging to print a message in the serial log. > > Suggested-by: Edwin Torok <edvin.to...@citrix.com> > Signed-off-by: Jane Malalane <jane.malal...@citrix.com> > --- > CC: Jan Beulich <jbeul...@suse.com> > CC: Andrew Cooper <andrew.coop...@citrix.com> > CC: "Roger Pau Monné" <roger....@citrix.com> > CC: Wei Liu <w...@xen.org> > --- > xen/arch/x86/dom0_build.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c > index fe24e11b37..e57cc80ef0 100644 > --- a/xen/arch/x86/dom0_build.c > +++ b/xen/arch/x86/dom0_build.c > @@ -240,6 +240,11 @@ unsigned int __init dom0_max_vcpus(void) > if ( max_vcpus > limit ) > max_vcpus = limit; > > + if ( max_vcpus < opt_dom0_max_vcpus_max && max_vcpus > > opt_dom0_max_vcpus_min ) > + printk(XENLOG_INFO "Dom0 using %d vCPUs conflicts with request to > use" > + " %d node(s), using up to %d vCPUs\n", opt_dom0_max_vcpus_max, > + dom0_nr_pxms, max_vcpus); > + > return max_vcpus; > } > Here I was debating whether to use a printk or a dprintk, as although this would be useful for debugging, it gives general info on dom0 vCPU topology, as does for e.g. 'Dom0 has maximimum ... vCPUS'. However, I defer to the maintainers, as I'm still getting acquainted with Xen (I also understand this patch is of minor importance).
Thanks, Jane.
