On 2016/4/23 15:03, Andrew Jones wrote: > On Sat, Apr 23, 2016 at 09:17:25AM +0800, Shannon Zhao wrote: >> > >> > >> > On 2016/4/22 20:25, Andrew Jones wrote: >>> > > On Thu, Apr 21, 2016 at 02:23:50PM +0800, Shannon Zhao wrote: >>>>> > >> > From: Shannon Zhao <shannon.z...@linaro.org> >>>>> > >> > >>>>> > >> > This /distance-map node is used to describe the accessing distance >>>>> > >> > between NUMA nodes. >>>>> > >> > >>>>> > >> > Signed-off-by: Shannon Zhao <shannon.z...@linaro.org> >>>>> > >> > --- >>>>> > >> > hw/arm/virt.c | 30 ++++++++++++++++++++++++++++++ >>>>> > >> > 1 file changed, 30 insertions(+) >>>>> > >> > >>>>> > >> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c >>>>> > >> > index 56d35c7..814a1eb 100644 >>>>> > >> > --- a/hw/arm/virt.c >>>>> > >> > +++ b/hw/arm/virt.c >>>>> > >> > @@ -40,6 +40,7 @@ >>>>> > >> > #include "sysemu/device_tree.h" >>>>> > >> > #include "sysemu/sysemu.h" >>>>> > >> > #include "sysemu/kvm.h" >>>>> > >> > +#include "sysemu/numa.h" >>>>> > >> > #include "hw/boards.h" >>>>> > >> > #include "hw/loader.h" >>>>> > >> > #include "exec/address-spaces.h" >>>>> > >> > @@ -203,6 +204,9 @@ static VirtBoardInfo *find_machine_info(const >>>>> > >> > char *cpu) >>>>> > >> > >>>>> > >> > static void create_fdt(VirtBoardInfo *vbi) >>>>> > >> > { >>>>> > >> > + unsigned int i, j, number, count; >>> > > s/count/index/ ? >>> > > >>>>> > >> > + uint64_t *matrix; >>>>> > >> > + >>>>> > >> > void *fdt = create_device_tree(&vbi->fdt_size); >>>>> > >> > >>>>> > >> > if (!fdt) { >>>>> > >> > @@ -239,6 +243,32 @@ static void create_fdt(VirtBoardInfo *vbi) >>>>> > >> > "clk24mhz"); >>>>> > >> > qemu_fdt_setprop_cell(fdt, "/apb-pclk", "phandle", >>>>> > >> > vbi->clock_phandle); >>>>> > >> > >>>>> > >> > + if (nb_numa_nodes <= 0) { >>>>> > >> > + return; >>>>> > >> > + } >>>>> > >> > + >>>>> > >> > + /* Add /distance-map node for NUMA */ >>>>> > >> > + qemu_fdt_add_subnode(fdt, "/distance-map"); >>>>> > >> > + qemu_fdt_setprop_string(fdt, "/distance-map", "compatible", >>>>> > >> > + "numa-distance-map-v1"); >>>>> > >> > + >>>>> > >> > + number = nb_numa_nodes * nb_numa_nodes * 6; >>>>> > >> > + matrix = g_malloc0(number * sizeof(uint64_t)); >>>>> > >> > + for (i = 0; i < nb_numa_nodes; i++) { >>>>> > >> > + for (j = 0; j < nb_numa_nodes; j++) { >>>>> > >> > + count = (i * nb_numa_nodes + j) * 6; >>>>> > >> > + matrix[count++] = 1; >>>>> > >> > + matrix[count++] = i; >>>>> > >> > + matrix[count++] = 1; >>>>> > >> > + matrix[count++] = j; >>>>> > >> > + matrix[count++] = 1; >>>>> > >> > + matrix[count++] = (i == j) ? 10 : 20; >>>>> > >> > + } >>>>> > >> > + } >>>>> > >> > + qemu_fdt_setprop_sized_cells_from_array(fdt, "/distance-map", >>>>> > >> > + "distance-matrix", >>>>> > >> > number / 2, >>>>> > >> > + matrix); >>> > > I had to read qemu_fdt_setprop_sized_cells_from_array to understand why >>> > > above we're using 6 instead of 3, and then placing all the 1's in every >>> > > other slot, and then dividing number by 2 here. Is using this function >>> > > worth the confusion? >>> > > >>> > > I think the following would greatly improve reviewability, and shave off >>> > > a bit of boot time (by not having to alloc more mem and copy the >>> > > matrix). >>> > > >>> > > uint32_t *matrix; >>> > > >>> > > number = nb_numa_nodes * nb_numa_nodes * 3; >>> > > matrix = g_malloc0(number * sizeof(uint32_t)); >>> > > for (i = 0; i < nb_numa_nodes; i++) { >>> > > for (j = 0; j < nb_numa_nodes; j++) { >>> > > count = (i * nb_numa_nodes + j) * 3; >>> > > matrix[count++] = cpu_to_be32(i); >>> > > matrix[count++] = cpu_to_be32(j); >>> > > matrix[count++] = cpu_to_be32(i == j ? 10 : 20); > I noticed that /distance-map is an optional node by the latest version > of the spec. In its absence default values will be used. Do we plan on > putting anything other then the 10s and 20s here? If not, then we can > leave it to Linux to determine what the defaults should be, and it'll > use them by itself if we leave this node out. > Agree. I thought this before. It could not provide this /distance-map node as well as it doesn't provide SLIT table for ACPI. So I'll drop this patch.
Thanks, -- Shannon