linux adding some NUMA support

lib/std/os/linux.zig

@@ -1519,6 +1519,22 @@ pub fn sched_getaffinity(pid: pid_t, size: usize, set: *cpu_set_t) usize {
     return 0;
 }
 
+pub fn getcpu(cpu: *u32, node: *u32) usize {
+    return syscall3(.getcpu, cpu, node, null);
+}
+
+pub fn sched_getcpu() usize {
+    var cpu: u32 = undefined;
+    const rc = syscall3(.getcpu, &cpu, null, null);
+    if (@bitCast(isize, rc) < 0) return rc;
+    return @intCast(usize, cpu);
+}
+
+/// libc has no wrapper for this syscall
+pub fn mbind(addr: ?*anyopaque, len: u32, mode: i32, nodemask: *const u32, maxnode: u32, flags: u32) usize {
+    return syscall6(.mbind, addr, len, mode, nodemask, maxnode, flags);
+}
+
 pub fn epoll_create() usize {
     return epoll_create1(0);
 }