On Thu, Nov 17, 2022, Mathieu Desnoyers wrote: > On 2022-11-17 14:10, Sean Christopherson wrote: > > On Thu, Nov 17, 2022, Mathieu Desnoyers wrote: > > > On 2022-11-14 15:49, Sean Christopherson wrote: > > > > On Fri, Nov 11, 2022, Mathieu Desnoyers wrote: > > > > > On 2022-11-10 23:41, Andy Lutomirski wrote: > > > > > > On Thu, Nov 3, 2022 at 1:05 PM Mathieu Desnoyers > > > > > > <mathieu.desnoyers@xxxxxxxxxxxx> wrote: > > > > > > Also, in my mind "virtual cpu" is vCPU, which this isn't. Maybe > > > > > > "compacted cpu" or something? It's a strange sort of concept. > > > > > > > > > > I've kept the same wording that has been introduced in 2011 by Paul Turner > > > > > and used internally at Google since then, although it may be confusing if > > > > > people expect kvm-vCPU and rseq-vcpu to mean the same thing. Both really end > > > > > up providing the semantic of a virtually assigned cpu id (in opposition to > > > > > the logical cpu id on the system), but this is much more involved in the > > > > > case of KVM. > > > > > > > > I had the same reaction as Andy. The rseq concepts don't worry me so much as the > > > > existence of "vcpu" in mm_struct/task_struct, e.g. switch_mm_vcpu() when switching > > > > between KVM vCPU tasks is going to be super confusing. Ditto for mm_vcpu_get() > > > > and mm_vcpu_put() in the few cases where KVM currently does mmget()/mmput(). > > > > > > I'm fine with changing the wording if it helps make things less confusing. > > > > > > Should we go for "compact-cpu-id" ? "packed-cpu-id" ? Other ideas ? > > > > What about something like "process-local-cpu-id" to capture that the ID has meaning > > only within the associated address space / process? > > Considering that the shorthand for "memory space" is "VM" in e.g. "CLONE_VM" No objection from me for "vm", I've already had to untrain myself and remember that "vm" doesn't always mean "virtual machine" :-) > clone(2) flags, perhaps "vm-cpu-id", "vm-local-cpu-id" or "per-vm-cpu-id" ? I have a slight preference for vm-local-cpu-id, but any of 'em work for me.
