On Fri, 8 Jul 2016 15:25:33 +1000 David Gibson <da...@gibson.dropbear.id.au> wrote:
> On Thu, Jul 07, 2016 at 06:11:31PM +0200, Greg Kurz wrote: > > On Thu, 7 Jul 2016 20:20:23 +0530 > > Bharata B Rao <bhar...@linux.vnet.ibm.com> wrote: > > > > > Conditonally set stable_cpu_id for CPU threads that are created as part > > > of spapr CPU cores. The use of stable_cpu_id is enabled for pseries-2.7 > > > onwards. > > > > > > > The last sentence is a bit confusing since the enablement actually happens > > in patch 5/5. > > > > > Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> > > > --- > > > hw/ppc/spapr_cpu_core.c | 7 +++++++ > > > 1 file changed, 7 insertions(+) > > > > > > diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c > > > index b104778..0ec3513 100644 > > > --- a/hw/ppc/spapr_cpu_core.c > > > +++ b/hw/ppc/spapr_cpu_core.c > > > @@ -293,8 +293,15 @@ static void spapr_cpu_core_realize(DeviceState *dev, > > > Error **errp) > > > for (i = 0; i < cc->nr_threads; i++) { > > > char id[32]; > > > obj = sc->threads + i * size; > > > + CPUState *cs; > > > > > > object_initialize(obj, size, typename); > > > + cs = CPU(obj); > > > + > > > + /* Use core_id (which is actually cpu_dt_id) as stable CPU id */ > > > > > > > It isn't what I had in mind. More something like below: > > > > In ppc_spapr_init(): > > > > for (i = 0; i < spapr_max_cores; i++) { > > spapr->cores[i]->stable_id = i * smp_threads; > > } > > > > > > In spapr_cpu_core_realize(): > > > > for (j = 0; j < cc->nr_threads; j++) { > > stable_cpu_id = cc->stable_id + j; > > } > > > > So we need to introduce cc->stable_id. > > No, we don't. Cores have had a stable ID since they were introduced. > I agree core_dt_id is stable but it is a DT concept. static void ppc_spapr_init(MachineState *machine) { [...] for (i = 0; i < spapr_max_cores; i++) { int core_dt_id = i * smt; [...] object_property_set_int(core, core_dt_id, CPU_CORE_PROP_CORE_ID, &error_fatal); This patch produces stable_cpu_id in the [0...smt * smp_cores) range. I find it awkward it depends on the host setup. I'm suggesting we introduce cc->stable_id to be able to compute a simple stable_cpu_id in the range [0...max_cpus), like x86 and ARM. > Instead we should be setting the thread stable ids based on the core > stable id. > > > I think stable_cpu_id is the prerequisite to compute both cpu_dt_id and > > instance_id. > > > > Makes sense ? > > > > > + if (cs->has_stable_cpu_id) { > > > + cs->stable_cpu_id = cc->core_id + i; > > > + } > > > snprintf(id, sizeof(id), "thread[%d]", i); > > > object_property_add_child(OBJECT(sc), id, obj, &local_err); > > > if (local_err) { > > >
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