Fix more synchronization.

src/arch/x86_64/gdt.rs

@@ -245,6 +245,8 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: LogicalCpuId) {
         #[cfg(feature = "profiling")]
         profiling: None,
     };
+
+    crate::percpu::init_tlb_shootdown(cpu_id, &mut pcr.percpu);
 }
 #[derive(Copy, Clone, Debug)]
 #[repr(packed)]

src/arch/x86_shared/device/local_apic.rs

@@ -149,7 +149,6 @@ impl LocalApic {
         }
         self.set_icr(icr);
     }
-    // Not used just yet, but allows triggering an NMI to another processor.
     pub fn ipi_nmi(&mut self, apic_id: u32) {
         let shift = if self.x2 { 32 } else { 56 };
         self.set_icr((u64::from(apic_id) << shift) | (1 << 14) | (0b100 << 8));