On Mon, Apr 16, 2018 at 07:47:29PM +0300, Serhii Popovych wrote:
> Bharata B Rao wrote:
> > On Wed, Apr 11, 2018 at 02:41:59PM -0400, Serhii Popovych wrote:
> >> Now recent kernels (i.e. since linux-stable commit a346137e9142
> >> ("powerpc/numa: Use ibm,max-associativity-domains to discover possible
> >> nodes")
> >> support this property to mark initially memory-less NUMA nodes as
> >> "possible"
> >> to allow further memory hot-add to them.
> >>
> >> Advertise this property for pSeries machines to let guest kernels detect
> >> maximum supported node configuration and benefit from kernel side change
> >> when hot-add memory to specific, possibly empty before, NUMA node.
> >>
> >> Signed-off-by: Serhii Popovych <spopo...@redhat.com>
> >> ---
> >> hw/ppc/spapr.c | 10 ++++++++++
> >> 1 file changed, 10 insertions(+)
> >>
> >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >> index a81570e..c05bbad 100644
> >> --- a/hw/ppc/spapr.c
> >> +++ b/hw/ppc/spapr.c
> >> @@ -910,6 +910,13 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr,
> >> void *fdt)
> >> 0, cpu_to_be32(SPAPR_MEMORY_BLOCK_SIZE),
> >> cpu_to_be32(max_cpus / smp_threads),
> >> };
> >> + uint32_t maxdomains[] = {
> >> + cpu_to_be32(4),
> >> + cpu_to_be32(0),
> >> + cpu_to_be32(0),
> >> + cpu_to_be32(0),
> >> + cpu_to_be32(nb_numa_nodes - 1),
> >> + };
> >>
> >> _FDT(rtas = fdt_add_subnode(fdt, 0, "rtas"));
> >>
> >> @@ -946,6 +953,9 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr,
> >> void *fdt)
> >> _FDT(fdt_setprop(fdt, rtas, "ibm,associativity-reference-points",
> >> refpoints, sizeof(refpoints)));
> >>
> >> + _FDT(fdt_setprop(fdt, rtas, "ibm,max-associativity-domains",
> >> + maxdomains, sizeof(maxdomains)));
> >> +
> >> _FDT(fdt_setprop_cell(fdt, rtas, "rtas-error-log-max",
> >> RTAS_ERROR_LOG_MAX));
> >> _FDT(fdt_setprop_cell(fdt, rtas, "rtas-event-scan-rate",
> >> --
> >> 1.8.3.1
> >
> > This commit causes hash guest with latest guest kernel to hang at early
> > boot.
>
> I use v4.16 tag from stable and can't reproduce on P8 machine reported
> issue.
>
> Could you please share more details about your setup, kernel commit id
> you spot problem?
I am on 4.16.0-rc7 (commit id: 0b412605ef5f)
BTW this happens only for non-NUMA guest.
Regards,
Bharata.
