On Mon, Mar 20, 2017 at 04:11:14PM -0300, Eduardo Habkost wrote: > On Mon, Mar 20, 2017 at 03:12:44PM +0100, Laurent Vivier wrote: > > Since commit 224245b ("spapr: Add LMB DR connectors"), NUMA node > > memory size must be aligned to 256MB (SPAPR_MEMORY_BLOCK_SIZE). > > > > But when "-numa" option is provided without "mem" parameter, > > the memory is equally divided between nodes, but 8MB aligned. > > This can be not valid for pseries. > > > > In that case we can have: > > $ ./ppc64-softmmu/qemu-system-ppc64 -m 4G -numa node -numa node -numa node > > qemu-system-ppc64: Node 0 memory size 0x55000000 is not aligned to 256 MiB > > > > With this patch, we have: > > (qemu) info numa > > 3 nodes > > node 0 cpus: 0 > > node 0 size: 1280 MB > > node 1 cpus: > > node 1 size: 1280 MB > > node 2 cpus: > > node 2 size: 1536 MB > > > > Signed-off-by: Laurent Vivier <lviv...@redhat.com>
In agree with Eduardo's suggested comment changes. Apart from that, Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> Eduardo, do you want to take the final spin through your tree, or should I take it through mine? > > The code looks good, but a few comments explaining the reason for > the numa_mem_align_shift values would be interesting. Additional > comments below: > > > --- > > v2: > > - remove dtc > > - Add a field in MachineClass to only modify the > > numa node memory alignment value for pseries-2.9 > > and upper. > > > > hw/core/machine.c | 3 +++ > > hw/ppc/spapr.c | 2 ++ > > include/hw/boards.h | 1 + > > numa.c | 4 ++-- > > 4 files changed, 8 insertions(+), 2 deletions(-) > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > index 0d92672..2ad5ab5 100644 > > --- a/hw/core/machine.c > > +++ b/hw/core/machine.c > > @@ -396,6 +396,9 @@ static void machine_class_init(ObjectClass *oc, void > > *data) > > mc->default_ram_size = 128 * M_BYTE; > > mc->rom_file_has_mr = true; > > > > + /* numa node memory size aligned on 8MB by default */ > > + mc->numa_mem_align_shift = 23; > > + > > This could include the original "On Linux, each node's border has > to be 8MB aligned" comment from parse_numa_opts(), to explain the > reason for the 8MB default. > > > object_class_property_add_str(oc, "accel", > > machine_get_accel, machine_set_accel, &error_abort); > > object_class_property_set_description(oc, "accel", > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > index 6ee566d..1e72fe8 100644 > > --- a/hw/ppc/spapr.c > > +++ b/hw/ppc/spapr.c > > @@ -3096,6 +3096,7 @@ static void spapr_machine_class_init(ObjectClass *oc, > > void *data) > > xic->ics_resend = spapr_ics_resend; > > xic->icp_get = spapr_icp_get; > > ispc->print_info = spapr_pic_print_info; > > + mc->numa_mem_align_shift = 28; > > A comment explaining why spapr requires 256MB alignment would be > nice. > > > } > > > > static const TypeInfo spapr_machine_info = { > > @@ -3180,6 +3181,7 @@ static void > > spapr_machine_2_8_class_options(MachineClass *mc) > > { > > spapr_machine_2_9_class_options(mc); > > SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_8); > > + mc->numa_mem_align_shift = 23; > > } > > > > DEFINE_SPAPR_MACHINE(2_8, "2.8", false); > > diff --git a/include/hw/boards.h b/include/hw/boards.h > > index 269d0ba..31d9c72 100644 > > --- a/include/hw/boards.h > > +++ b/include/hw/boards.h > > @@ -135,6 +135,7 @@ struct MachineClass { > > bool rom_file_has_mr; > > int minimum_page_bits; > > bool has_hotpluggable_cpus; > > + int numa_mem_align_shift; > > > > HotplugHandler *(*get_hotplug_handler)(MachineState *machine, > > DeviceState *dev); > > diff --git a/numa.c b/numa.c > > index e01cb54..98e4d02 100644 > > --- a/numa.c > > +++ b/numa.c > > @@ -338,12 +338,12 @@ void parse_numa_opts(MachineClass *mc) > > if (i == nb_numa_nodes) { > > uint64_t usedmem = 0; > > > > - /* On Linux, each node's border has to be 8MB aligned, > > + /* On Linux, each node's border has to be aligned, > > * the final node gets the rest. > > */ > > I assume that the 256MB alignment in spapr is not just because of > Linux (is it?). This makes the comment misleading. > > I would rewrite it to something like: "Align each node according > to the alignment requirements of the machine class". > > > > for (i = 0; i < nb_numa_nodes - 1; i++) { > > numa_info[i].node_mem = (ram_size / nb_numa_nodes) & > > - ~((1 << 23UL) - 1); > > + ~((1 << mc->numa_mem_align_shift) > > - 1); > > usedmem += numa_info[i].node_mem; > > } > > numa_info[i].node_mem = ram_size - usedmem; > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature