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);
}
}
qemu_fdt_setprop(fdt, "/distance-map", "distance-matrix",
matrix, number * sizeof(uint32_t));
> + g_free(matrix);
Also, I think it would nicer if all this was put in its own function, and
then just add the following to create_fdt.
if (nb_numa_nodes) {
virt_fdt_create_distance_map(fdt);
}
> }
>
> static void fdt_add_psci_node(const VirtBoardInfo *vbi)
> --
> 2.0.4
Otherwise per https://lkml.org/lkml/2016/4/8/572 it looks good.
Thanks,
drew
